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GH688,GA628, Standard Electrical Repairs
Approved according to 1776-2/FEA 209 544
Trouble-shooting instruction GH 688/GA 628
Standard electrical repairs
4/00021-2/FEA 209 544/1.G
GH688,GA628, Standard Electrical Repairs
Table of contents
1 Conditions .......................................................................................... 3
1.1 1.2 1.3 Component classes. ......................................................................... 3 Abbreviations. ................................................................................. 4 Pin placements ................................................................................ 6
2 3 4 5 6 7 8 9 10 11
No serv or can´t place a call. ............................................................ 8 Doesn't start. ................................................................................... 13 Audio. ............................................................................................... 22 Display. ............................................................................................ 30 Charging. ......................................................................................... 38 SIM fault ("Insert card"). .............................................................. 43 Keyboard. ........................................................................................ 48 Illumination and buzzer. ................................................................ 55 RTC .................................................................................................. 63 Component lists ............................................................................... 65
11.1 Explanation ................................................................................... 65 11.2 Mounting drawing tables ............................................................. 66
GH688 .............................................................................................. 66 GA628 .............................................................................................. 66
11.3 Component list GH688 ................................................................. 67
11.3.1 Revision change tables GH688 ......................................................... 80 Revision change table for 2/ROA 117 3307/1 and 2/ROA 117 3307/5, 2/ROA 117 3307/3 80 Revision change table for 2/ROA 117 3307/4 2/ROA 11 73307/6 ............. 84
11.4 Component list GA628 ................................................................. 88
11.4.1 Revision change tables GA628 ....................................................... 100 Revision change table for 2/ROA 117 3308/1, 2/ROA 117 3308/2 .......... 100 Revision change table for 2/ROA 117 3308/3, 2/ROA 117 3308/4 .......... 104 Revision change table for 2/ROA 117 3308/5, 2/ROA 117 3308/7 .......... 109
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1 Conditions
1.1 Component classes.
All the components in the phone are divided into classes and after every component in the troubleshooting guide you have a class written. The components are divided into four classes: A, B, C and D.The class of the component depends on how much of the phone's performance is affected when replacing it.
Class A and B:A test call towards the "real" net (not only towards a GSM test instrument) and run it through the normal tests is enough to verify the functionality since the performance of the phone is only slightly affected. Class C: Since the tolerances of the component are so great it can substantially affect the performance of the phone you need to calibrate it at station level after replacing the component. Class D components need to be calibrated at board level using very advanced equipment and may therefore not be replaced.
Class D:
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1.2 Abbreviations.
A: B: C: D: F: G: H: J: L: N: R: S: U: V: X: Z: The power module at some phones. Crystal. Capacitor. Digital circuit. Over voltage protection. VCO. Buzzer, LED, pads for display. Connector. Coil. Analogue circuit. Resistor. Keyboard pads. BALUN. A circuit that converts a signal from balanced to unbalanced or the opposite. Transistor or diode. Contact surface at the circuit board. Filter.
AGND: DCIO: DCON:
Ground for analogue signals. DC voltage used for charging the battery through the system connector. Logical signal from the processor that keeps the phone running after you've released the On/Off key.
EXTAUD: Input signal at the system connector that the processor uses to determine if there's any external audio equipment attached. EXTAUDI: The same signal as the EXTAUD signal but at the processor side. GND: LED3K: ONSRQ: PORTHF: PHF1: REGON: RTC: Ground. Logical signal used to activate the background illumination. Voltage from the On/Off key that starts the phone. Input signal at the system connector that the processor uses to determine if there's any handsfree equipment attached. The same signal as PORTHF but at the processor side. Logical signal that activates the voltage regulators. Real time clock. The clock that keeps track of time and date.
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SIMCLK: SIMDAT: SIMRST: SIMVCC: SWDC: VANA: VBATT: VDIG: VDSP: VLCD: VRAD: VRPAD: VRTC:
Clock signal from the processor used for communications with the SIM. Data signal from the processor used for communications with the SIM. Reset signal from the processor used for communications with the SIM. Feed voltage for the SIM. Switched VBATT. DC voltage for the analogue part of the logic (N800). Battery voltage. DC voltage for the processor and memory. DC voltage for the DSP (Digital Signal Processor). DC voltage for the display that controls the contrast. DC voltage for the radio part except the synthesizer. DC voltage for the radio part in D600 (also used for the top diode and the buzzer). DC voltage for the real time clock.
VSIMPAD: VDIG voltage that has been switched up to 5V used for SIM. VVCO: DC voltage for the synthesizer.
I2C: LO: PWM:
Two line serial communications standard using one clock and one data line. Local oscillator. Pulse width modulation.
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1.3 Pin placements
Single diode (PIN diode).
Electrolytic capacitor.
Double diode or single transstor.
Five pin circuit (usually voltage regulator).
Double transistor.
Eight pin circuit.
VCO circuit
Crystal
Sixteen pin circuit
Twenty pin circuit
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N800
D900
D600
D620
D610
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2 No serv or can´t place a call.
2.1 Find out if the problem is Tx- or Rx-related.
Connect the phone (with signaling program) to a GSM instrument and try to get serv at 68.5dBm signal strength. ˇ If the phone gets serv proceed to section 2.2. ˇ If it doesn't get serv it's probably a problem located in the LO-part or the losses in the signal path are too great. Open the phone and check for liquid damage. The component side of the board is shown in fig. 2.1.
Fig. 2.1 Check the antenna connector, X401 (class A, fig. 2.2), and make sure that it isn't damaged or dirty (glue, varnish, oxide...) and that the solderings aren't faulty.
Fig. 2.2 Look for faulty solderings at G350 and C359 (fig. 2.3).
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Fig. 2.3 Measure the resistance of C853 (class B, >100 kohms, fig. 2.4).
Fig. 2.4
Give the board power and start it up. Measure VVCO (~3.8V) at V451 pad 3 and VRAD (~3.8V) at C457 (fig. 2.5). ˇ If any of the voltages are incorrect, proceed to chapter 3 ("Doesn´t start"-fault).
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Fig. 2.5 Measure the DC voltage at pin 1 and 2 of G350. The voltage at pin 1 (control voltage) should always vary between ~0.8V - ~2.8V (usually starts at ~1.7V). The voltage at pin 2 (feed voltage) also varies but usually starts at ~3.3V (fig. 2.3). ˇ If the feed voltage is incorrect (usually no voltage at all), check the soldering at D600 pin 102 (fig. 2.1). * If the soldering isn't faulty, send the phone to the next level. ˇ If the control voltage is incorrect (usually ~0V or ~3.6V), check if C370 (class B) and R357 (class B) are mounted (both of them in fig. 2.3). * If that is the case, replace N350 (class B, fig. 2.3). * If that doesn't help, replace G350 (class B, fig. 2.3). Measure the resistance of C540, C541, C542, C543, C544 and C545 (all of them class B, >200 kohms, fig. 2.3) Check the solderings at C826 (fig. 2.4), Z201, Z500, Z501 and Z502 (fig. 2.3).
If the problem isn't solved, send the phone to the next level.
2.2
Connect a call at powerlevel 5 using an instrument with 68.5dBm signal strength.
ˇ If it works, proceed to section 2.3. ˇ If it doesn't work, open the phone and check for liquid damage. Make sure the ground foil around the antenna connector isn't dirty. Check the antenna connector, X401 (class A, fig. 2.2), and make sure that it isn't damaged or dirty (glue, varnish, oxide...) and that the solderings aren't faulty. Replace the back cover and try again. ˇ If it doesn't work it most likely means that the problem is Tx-related. Check if C300, C403, L300, V300, V301 or V302 (all class A, fig. 2.6) are burnt.
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Fig. 2.6 Check soldering at G300 (fig. 2.5). Measure the resistance of C853 (class B, >100 kohms, fig. 2.4). Measure the resistance of R403 (class B, <1 ohms, fig. 2.6). Measure the resistance of L300 (class A, <1 ohms, fig. 2.6).
If the problem isn't solved, send the phone to the next level.
2.3
Read the Rx-level and output power values from the instrument while the call is still connected.
ˇ If the Rx-level value is at 40 - 46 steps, check that the output power is 3135dBm. * If it is correct it means that the phone probably isn't faulty. Lower the signal strength at the instrument to 102dBm and make sure that the Rx-level value is 6-12 steps and that the Rx-quality value is 0-2 steps. * Try running the phone through the test again. * If the phone passes the test but doesn't manage to connect a call at the "real" net, make sure that it isn't because it is stolen. If it isn't, replace D600 (class B, fig. 2.1). * If you get one of these error messages; "phase and frequency error", "burst timing", "power level 5-19", "Rx-quality" or "Rxlevel" that differs slightly from the default values, try replacing the
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back cover and run the phone through the test again. This applies especially for the GA 628. ˇ If the output power is too low or the Rx-quality value is too high, send the phone to the next level. ˇ If the Rx-level value is too high, the phone has to be calibrated and therefore you have to send the phone to the next level. ˇ If the Rx-level value is below 40 steps at 68.5dBm signal strength or below 6 steps at 102dBm signal strength, the problem is Rx-related. Open the phone and check for liquid damage. Check the antenna connector, X401 (class A, fig. 2.2), and make sure that it isn't damaged or dirty (glue, varnish, oxide...) and that the solderings aren't faulty. Measure the resistance from C426 (fig. 2.2, measure from the marked side) to ground (>1 Mohms). The resistance is usually only a few ohms when Z200 (class B, fig. 2.7) is broken.
Fig. 2.7 Measure the resistance from the anode of V403 (class B, fig. 2.2) to ground (~60 kohms). ˇ If it's less (a few kohms), lift one of the V402 pins from the pad and measure again at the same place. If it's correct (~60 kohms), replace V402. ˇ If the resistance is still too low, replace both diodes. Measure again after replacing the component(s). ˇ If the resistance is still too low, measure the resistance of R421 and R422 (both of class B, 100 kohms, fig. 2.2). Both the resistors are 100 kohms but when you measure them the instrument will show ~60 kohms. Check the solderings at C826 (fig. 2.4), Z201, Z500, Z501 and Z502 (fig. 2.3). Measure the resistance of C540, C541, C542, C543, C544 and C545 (all of them class B, >200 kohms, fig. 2.3)
If the problem isn't solved, send the phone to the next level.
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3 Doesn't start.
3.1 Find out if the phone will start by using the On/Off-button.
Insert a fully charged battery and press the On/Off-button. ˇ If the phone doesn't start, proceed to section 3.2 ˇ If the phone starts, check the charging function by connecting a charger at the system connector. If the phone doesn't charge, proceed to chapter 6 ("Charging"-fault). If the phone starts (lights the background illumination, asks for SIM/PIN, seeks the net...) and charges it's probably not faulty or the problem is intermittent. Open the phone and make a visual examination of the circuit board. The component side of the board is shown in fig. 3.1.
Fig. 3.1 Check for liquid damages anywhere at the board. Also check for burnt or damaged pads at the system connector and faulty soldering at, for instance, D600, D610 and D620 (fig. 3.2).
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GH688
GA 628
Fig. 3.2 As soon as the problem is solved, send the phone through the flow as usual.
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3.2 Visual check.
Make a visual check. Make sure that the battery screws are intact and properly mounted, that the isolator sleeve (GH 688) is properly mounted, that the volume keys aren't stuck and that the system connector isn't dirty or liquid damaged. Continue at 3.3.
3.3
Current consumption with On/off-key pressed.
Insert a dummy battery. ˇ If the phone consumes current immediately it usually means that C403 (class A, fig. 3.3) is faulty but first you should make sure that the frame gasket isn't in contact with the positive battery connector pad at the circuit board (fig. 3.4).
Fig. 3.3
Fig. 3.4
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Start the phone using the On/Off-key and check the current consumption. ˇ If the phone doesn't consume any current at all when the On/Off-key is pressed it is most likely liquid damaged. Open the phone and check this. Also check that the keyboard and the keyboard pads are functional and clean. ˇ If the phone consumes more than 200mA, remove the display elastomer and try again. * If the consumption is reduced it was probably the elastomer or the display. * If the consumption is just as high as before, proceed to section 3.4.3. ˇ If the phone consumes ~60mA (average, varies), the battery indicator blinks once or twice and then the phone turns itself off, then it's probably X820 (the pads to the volume flex film, fig. 3.5) or the volume flex film (J820) that is shorted out. Replace the flex film and if that doesn't work, proceed to section 3.2. * If the same phenomena arises without the On/Off-key being pressed it means that V704 is broken (fig. 3.2).
Fig. 3.5 ˇ If the phone consumes 1-200mA, starts (asks for SIM/searches for the net...etc...) and works as long as you keep the On/Off-key pressed, proceed to section 3.4.4. ˇ If the phone doesn't start, try to program it in the flash programmer. * If it doesn't start in the flash programmer, proceed to section 3.4.1 * If you are able to program the phone in the flash programmer but it doesn't start afterwards or if it is troublesome when trying to program it, proceed to section 3.4.2. * If the phone starts after programming it in the flash-programmer then the problem is probably solved, but to eliminate intermittent errors check the circuit board for liquid damage or faulty solderings on D600, D610 and D620 (fig. 3.2).
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3.4 Measuring at a powered circuit board.
3.4.1 Doesn't start in the flash programmer.
Open the phone and check for liquid damage. Make sure the system connector pads aren't burnt. Place the board in the fixture. Start it up and keep it running by keeping DCIO high. Check VDIG and VDSP voltages (~3.2 V, fig. 3.2). ˇ If any of the voltages are too low, measure the resistance to ground (VDIG > 500 ohms, VDSP > 25 kohms). * If the resistances are correct, replace the corresponding circuit (VDIG N702, VDSP N701, both of class A). * If the resistance is too low, send the phone to next level. ˇ If any of the voltages are too high, replace the corresponding circuit. Check the power reset voltage at C710 (fig. 3.2, >3V). ˇ If it's lower, replace N450 (class A, fig. 3.6) and try again. * If it didn't work, replace C710 (class A).
Fig. 3.6 Check VRAD, VVCO and VRPAD (~3.8V, fig. 3.6). ˇ If all three voltages are wrong, measure the resistance from N450 pads 8, 11, 12, 13 and 14 to ground (~0 ohms). * If the resistance is too high there is a foil damage and the phone is to be discarded. * If it is correct, replace the circuit and eventually the transistors (V452, V451 and V450, all of them class A). ˇ If one or two of the voltages are wrong, measure the resistance from the corresponding voltage source to ground (>50 kohms). * If the resistance is correct, replace the corresponding transistor.
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* If that doesn't help, replace N450 (class A). * If the resistance of any of the voltage sources is too low, send the phone to the next level. Measure the amplitude of B551 pin 3 (class C, >1V t-t) with an oscilloscope, spectrum analyzer, frequency counter, diode probe... ˇ If the amplitude is too low, send the phone to the next level. Check for bad solderings at D600, D610 and D620 (fig 3.2). ˇ If they look ok, replace D600 (class B). * If that doesn't work, first replace D610 (class A) and then D620 (class A). Try to program the phone in the flash programmer for every circuit you replace. Don't replace any circuit if you haven't established the fact that B551 is working.
3.4.2 Is programmable in the flash programmer but doesn't start afterwards or is troublesome in the flash programmer.
Open the phone and check for liquid damages. Make sure the system connector pads aren't burnt. Insert the board in the fixture. Start it up and keep it going by keeping DCIO high. Check VDIG and VDSP (~3.2V, fig. 3.2). ˇ If any of the voltages are too low, measure the resistance from it to ground (VDIG >500 Ohms, VDSP >25 kohms). * If the resistance is correct, replace the corresponding circuit (VDIG N702 class A, VDSP N701 class A). * If the resistance is too low, send the phone to the next level. ˇ If any of the voltages are too high, replace the corresponding circuit. Check VRAD, VVCO and VRPAD (~3.8V, fig. 3.6). ˇ If all the voltages are incorrect, measure the resistance from N450 pads 8, 11, 12, 13 and 14 to ground (~0 ohms). * If any of the resistances are too high there is a foil damage and the phone should be discarded. * If all the resistances are correct, replace the circuit and eventually the transistors (V450, V451, V452, all class A). ˇ If one or two of the voltages are incorrect, measure the resistance from the incorrect voltage(s) to ground (>50 kohms). * If the resistance is correct replace the corresponding transistor. If that doesn't help, replace N450 (class A).
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* If the resistances from any of the voltages to ground are too low, send the phone to the next level. Make sure that there are no faulty solderings on D600, D610 and D620. ˇ If the solderings look good, replace D610 (class A). * If that doesn't help, first replace D600 (class B) and then D620 (class A). Try to program the phone in the flash programmer for every circuit you replace.
3.4.3 Consumes more than 200mA.
Open the phone and check for liquid damage. Make sure that the system connector pads aren't burnt. Insert the board in the fixture. Start it up and keep it going by keeping DCIO high. Check VDIG and VDSP (~3.2V, fig. 3.2). ˇ If any of the voltages are too low, measure the resistance from it to ground (VDIG >500 ohms, VDSP >25 kohms). * If the resistance is correct, replace the corresponding circuit (VDIG N702 class A, VDSP N701 class A). * If the resistance is too low, send the phone to the next level. ˇ If any of the voltages are too high, replace the corresponding circuit. Check VRAD, VVCO and VRPAD (~3.8V, fig. 3.6). ˇ If all three voltages are incorrect, measure the resistance from N450 pads 8, 11, 12, 13 and 14 to ground (0 ohms). * If the resistance is too high there is a foil damage and the phone should be discarded. * If the resistance is correct, replace the circuit and eventually transistors (V450, V451, V452, all class A). ˇ If one or two of the voltages are incorrect, measure the resistance to ground (>50 kohms). * If the resistance is correct, replace the corresponding transistor. * If that doesn't help, replace N450 (class A). * If the resistance from any of the voltages to ground is too low, send the phone to the next level.
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3.4.4 The phone works as long as the On/Off-key is pressed.
GH688
Open the phone and check for liquid damages. Make sure the system connector pads aren't burnt. Insert the board in the fixture. Start it up and keep it going by keeping DCIO high. Measure the voltage at C692 (~3.1V, fig. 3.2). ˇ If there is voltage, check the soldering at D600 pin 119. ˇ If there isn't voltage, measure the resistance of C692 (class A, >200 kohms). * If the resistance is correct, measure the input voltage at N706 pin 2 (VBATT) and the output voltage at N706 pin 3 (~3.5V). Make sure that the regulator has ground at N706 pin 1. There is a foil damage if the ground or VBATT is missing at N706 and the phone should be discarded. * If the input voltage and the ground are correct, replace N706 (class A). * If the output voltage is correct, measure the voltage at the positive side of the backup capacitor (C720, class A, ~3.1V). * If there is no voltage, replace V711 (class A). * If there is voltage, check the resistance from the positive side of C720 (fig. 3.5) to C692 (~0 ohms). * If the resistance is too high there is a foil damage and the phone should be discarded.
GA 628
Open the phone and check for liquid damage. Make sure that the system connector pads aren't burnt. Insert the board in the fixture. Start it up and keep it going by keeping DCIO high. Measure the voltage at C692 (~3.1V, fig. 3.2, the figure shows a GH 688 board but the capacitor is placed at the same location). ˇ If there is voltage, check the soldering at D600 pad 119. ˇ If there is no voltage, measure the resistance of C692 (class A, >200 kohms). * If the resistance is correct, measure VDIG. * If the voltage at VDIG is incorrect, see 3.4.1, 3.4.2 or 3.4.3. * If VDIG is correct, check the resistance from N702 pin5 (fig. 3.2) to C692 (~0 ohms).
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* If the resistance is too high, measure the resistance of R721 (class A, ~0 ohms). * If R721 is correct there is a foil damage and the phone should be discarded.
If the fault remains, send the phone to the next level.
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4 Audio.
4.1 Type of fault.
Make a call from the phone that is to be tested (later called the phone) to a phone that is working correctly (later called the reference phone). Check the function of the microphone and the earphone. Connect a handsfree unit to the system connector of the phone. Check the function of the phone's external connections by listening to the external speaker/earphone when talking in the reference phone and by listening to the earphone of the reference phone when talking in the external mic of the phone. ˇ If there is low or no sound in the earphone of the phone, proceed to section 4.2. ˇ If both the earphone and the handsfree speaker don't work, send the phone to the next level. ˇ If the sensitivity of the microphone is low (low or no sound in the reference phone), proceed to section 4.3. ˇ If both the microphone in the phone and the microphone of the handsfree don't work, send the phone to the next level. ˇ If both the microphone and the earphone don't work, proceed to section 4.4. ˇ If the microphone, the earphone and the handsfree don't work, send the phone to the next level. ˇ If the microphone of the handsfree doesn't work, proceed to section 4.5. ˇ If the speaker of the handsfree doesn't work, proceed to section 4.6. ˇ If both the microphone and the speaker of the handsfree don't work, proceed to section 4.7. ˇ If the phone sounds strange (the sound is distorted, scrambled, full of static or "chopped"), send the phone to the next level.
4.2 Earphone out of order.
Open the phone and check for liquid damages. Most of the earphone faults are mechanical. Therefore you should start with replacing the front (with the earphone) to one you know works and try again. ˇ If the fault remains, make sure the earphone connector (J810, fig. 4.1) is intact and correctly soldered.
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Fig. 4.1 Check the solderings of N800 (fig. 4.3). Fig. 4.2 shows the component side of the circuit board.
Fig. 4.2
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Fig. 4.3 If the fault remains, send the phone to the next level.
4.3 Microphone out of order.
Open the phone and check for liquid damages, especially around X830 (fig. 4.1) and below J603 (marked area A in fig. 4.2). Clean the system and microphone connector pads if needed. Most of the microphone faults are mechanical. Therefore you should start with replacing the front (with microphone) and elastomer to one you know works and try again. If the fault remains, measure the resistances of C850 (>100 kohms), C851 (>1 kohms), R817 (~1 kohms) and R819 (~1kohms, all of class A and in fig. 4.3). Note! The resistors are mounted at boards from revision R3A and above. Check the solderings of N800 (fig. 4.3). Replace C818 and C819 (fig. 4.3). If the fault still remains, send the phone to the next level.
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4.4
Both the earphone and microphone out of order.
Open the phone and check for liquid damages. Make sure there is no dirt or oxide between the components above the system connector pads (fig. 4.4 or marked area in fig. 4.5). Check very thoroughly!
Fig. 4.4 Clean the marked surface using alcohol and a brush. Note! The dirt can be very hard to remove but it's important to wash it away. Assemble the phone and try again as in 4.1. If the fault remains, replace F603 and F604. It's important to clean where the components are supposed to be before mounting new ones. Assemble the phone and try again as in 4.1. If it still doesn't work, open the phone, give the board power and start it up by pressing the On/Off key without the system cable connected. Measure the voltage at both sides of R601 and at D600 pin 70 (~5V, fig. 4.4 and 4.2, you follow the PHFI signal). Measure the voltage at both sides of R605 and at D600 pin 67 (~5V, fig. 4.4 and 4.2, you follow the EXTAUDI signal). ˇ If the voltage is low only at one side of R601 or R605, replace the corresponding resistor (fig. 4.4, both of class A). ˇ If the voltage is low at both sides of R601 or R605, check the VSIMPAD voltage at the marked sides of R635 and R636 (~5V, fig. 4.4). * If there is no voltage, check the resistance from the marked side of R635 or R636 to N705 pin 3 (~0 ohms, fig. 4.4 and 4.2). * If the resistance is too high there's a foil damage and the phone is to be discarded. * If the resistance is correct, proceed to section 4.3. * If there is VSIMPAD voltage at the marked side of R635 or R636, measure the resistances of them (both are ~22 kohms and in fig. 4.4). * If any of the resistances are incorrect, replace the corresponding resistor.
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* Measure the resistance from X602 pad 5 to ground (>100 kohms). * If it's too low, make sure there's no dirt or oxide between the components in the marked area (fig. 4.5). Clean thoroughly and measure again.
Fig. 4.5 * If the resistance still is too low, remove R601 (class A, fig. 4.4). * If the resistance increased, replace D600 (class B, fig. 4.2) and mount a new R601. * If the resistance didn't increase when removing R601 or it didn't help by replacing D600, send the phone to the next level.
* Measure the resistance from X602 pad 3 to ground (>100 kohms). * If it's too low, make sure there's no dirt or oxide between the components in the marked area (fig. 4.5). Clean thoroughly and measure again. * If the resistance still is too low, remove R605 (class A, fig. 4.4) and measure again. * If the resistance increased, replace D600 (class B, fig. 4.2) and mount a new R605. * If the resistance didn't increase when removing R605 or it didn't help by replacing D600, send the phone to the next level.
If all the above measured resistances are correct, but some of the voltages at R601 or R605 are low it's either caused by a slight short circuit due to dirt at the marked area in fig. 4.5, broken F603 or broken F604.
ˇ If the voltages at R601 and R605 are correct, connect a handsfree to the system connector. ˇ Measure the voltages at both sides of R601 (~0V, fig. 4.4) and at D600 pin 70 (~0V, fig. 4.2).
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* If the voltages aren't correct, check the soldering of D600 pin 70 (fig. 4.2). * If the soldering is correct, check the resistance of R601 (~1 kohms, class A). * If the resistance is correct, replace D600 (class B, fig. 4.2). * If the voltages are correct, check the solderings of N800, D600 and D900 (fig. 4.3 and 4.2).
If the fault remains, send the phone to the next level.
4.5 Handsfree microphone out of order.
The fault is caused by an interruption somewhere in the audio path from the handsfree microphone (connected at the system connector) to the input at N800. The audio path is shown in fig. 4.6.
Fig. 4.6 Open the phone and check for liquid damages, especially around the system connector (X602) pads 1, 2 and 4 (fig. 4.5). Measure the resistances of C850 (>100 kohms) and C851 (>1 kohms, both in fig. 4.3). Make sure all the components shown in fig. 4.6 (R830, R825, R802, R805, C835, C810 and C812) are mounted at the circuit board (fig. 4.3). Check the solderings of N800.
Give the board power and start it up by pressing the On/Off key without the system cable connected. Measure the voltage at the marked side of R825 (~3.1V, fig. 4.3). ˇ If the voltage isn't there or if it is incorrect, check the VANA voltage at the marked side of R830.
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* If the VANA voltage isn't correct, proceed to chapter 3 ("Doesn´t start"fault). * If VANA is correct, check the resistances of R830 (470 ohms), R825 (3.3 kohms) and C835 (>1 kohms, all of class A and in fig. 4.3). ˇ If the voltage at R825 is correct, check the resistances of C810 (>10 kohms), C812 (>100 kohms), R802 (~3.9 kohms) and R805 (~15 kohms, all four of class A and in fig. 4.3).
If the fault remains, send the phone to the next level.
4.6 Handsfree speaker out of order.
The fault is caused by an interruption somewhere in the audio path from the output of N800 to the handsfree speaker (connected at the system connector). The audio path is shown in fig. 4.7.
Fig. 4.7 Open the phone and check for liquid damages, especially around the system connector (X602) pads 1, 2 and 4 (fig. 4.5). Measure the resistances of C850 (>100 kohms) and C851 (>1 kohms, both in fig. 4.3). Make sure all the components shown in fig. 4.7 (R803, R804 and C813) are mounted at the circuit board (fig. 4.3). Check the solderings of N800 (fig. 4.3). Measure the resistances of R803 (~100 ohms), R804 (~100 kohms) and C813 (>100 kohms, all of class A and in fig. 4.3). Measure the resistance from the marked side of C813 to system connector (X602) pad 1 (~0 ohms, fig. 4.5) ˇ If the resistance is too high there's a foil damage and the phone is to be discarded.
If the fault remains, use the schematics.
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4.7
Both the microphone and the speaker of the handsfree out of order but the earphone and the microphone of the phone is working.
Open the phone and check for liquid damages, especially within the marked area above the system connector pads in fig. 4.5. Clean the marked area using alcohol and a brush. Measure the resistance from X602 pad 3 to the unmarked side of R635 (~0 ohms, fig. 4.4 and 4.5). Measure the resistance from X602 pad 5 to the unmarked side of R636 (~0 ohms, fig. 4.4 and 4.5). ˇ If any of the resistances are too high there's a foil damage and the phone is to be discarded. Measure the resistances of R601 and R605 (both are 1 kohms, of class A and in fig. 4.4). If all the resistances are correct, check the solderings of N800 and D600 (fig. 4.3 and 4.2).
If the fault remains, send the phone to the next level.
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5 Display.
5.1 Kind of fault.
Insert a fully charged battery and start it up using the On/Off-key. ˇ ˇ ˇ ˇ ˇ If it doesn't start, proceed to chapter 3 ("Doesn´t start"-fault). If the display is missing one or more segments, proceed to section 7.2. If the display is totally empty, proceed to section 7.3.1. If the contrast is low, proceed to section 7.3.2. If the all the segments in the display are "lit" proceed to section 7.4.
5.2 Segments are missing.
Open the phone and check for liquid damage. Replace the display. Observe that there are two kinds of display for GH 688.
5.3
The display is totally empty or the contrast is low.
5.3.1 The display is totally empty.
Start the phone using a dummy battery. Check the current consumption. ˇ If the phone consumes more than 200mA, check the display and see if it is damaged. * If it isn't, replace the elastomer and try again. * If it doesn't help, replace the display and try again. If the current consumption still is high, proceed to chapter 3 ("Doesn´t start"-fault). ˇ If the phone consumes less than 200mA, open the phone and check for liquid damages.
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5.3.2 The display is totally empty or the contrast is low.
Give the board power and start it up without a display mounted.
GH 688
The front side of the board is shown in fig. 5.1 Measure the voltages at V608 (class A) and V611 (class A). The GH 688 uses displays of two different brands, Philips and Seiko. Fig. 5.2 and 5.3 shows typical voltage values for both brands.
Fig. 5.1 Applies for KRC 114 245 and KRC 114 277 (Philips display):
Fig. 5.2
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Applies for KRC 114 279 (Seiko display):
Fig. 5.3 All of the values approximately 0.2V .
If one or more of the voltages are incorrect, measure the resistance if C633 (class A, >100 kohms, fig. 5.5) and C824 (class A, >25 kohms, fig. 5.2 and 5.3). ˇ If any of the resistances are too low, replace the corresponding capacitor. ˇ If both the resistances are correct, replace both diodes. * If any of the voltages at the diodes still are wrong after replacing them, check the solderings at D600 pads 95 and 96. * If they are correct, replace C634 and C632 (class A, fig. 5.2 and 5.3)
Applies for KRC 114 245 and KRC 114 277 (Philips display):
ˇ Make sure that there VLCD (~-3.7V) voltage at H622 pad 5 (fig. 5.5). * If there is no, check the resistances from H622 pad 5 to V611 pin 2 (~0 ohms) and from H622 pad 3 to ground (~0 ohms). * If any of the resistances are too high there is a foil damage and the phone is to be discarded.
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Fig. 5.5 If the problem isn't solved, send the phone to the next level.
Applies for KRC 114 279 (Seiko display):
ˇ Make sure that there VLCD (~-2.8V) voltage at H622 pad 5 (fig. 5.5). * If there is no, check the resistances from H622 pad 5 to V611 pin 2 (~0 ohms) and from H622 pad 3 to ground (~0 ohms). * If any of the resistances are too high there is a foil damage and the phone is to be discarded. If the problem isn't solved, proceed to section 5.4 (KRC 114 279).
GA 628
The front side of the circuit board is shown in fig. 5.7.
Measure the voltages at the V615 (class A) diode. Compare the measurement to the values in fig. 5.8.
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Fig. 5.7
Fig. 5.8 All of the values approximately 0.2V .
ˇ If any of the values differ, measure the resistance of C633 (class A, >100 kohms, fig. 5.10) and C824 (class A, >25 kohms, fig. 5.8). * If any of the resistances are too low, replace the corresponding capacitor. * If the resistances and VRPAD are correct, replace the diode. * If the voltages (except VRPAD) at the diode are still incorrect after replacing it, check the soldering at D600 pad 96. If it's correct, replace C636 (class A, fig. 5.8). * If VRPAD is incorrect, proceed to chapter 3 ("Doesn´t start"-fault). Make sure that the voltage VLCD (~5.4V) is at H624 pad 1. ˇ If it's not, check the resistances from H624 pad 1 to V615 pin 2 (~0 ohms) and from H624 pad 2 to ground (~0 ohms). * If any of the resistances are too high there is a foil damage and the phone should be discarded.
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Fig. 5.10 If the problem isn't solved, send the phone to the next level.
5.4 All the segments in the display are "lit".
Open the phone and check for liquid damage. ˇ Try with another display and elastomer. * If it doesn't help, give the board power and start it up without display.
GH 688 Applies for KRC 114 245 and KRC 114 277 (Philips display): Measure the voltages at the display pads H622 (fig. 5.5):
Pad # 1 2 3 4 5 6
Used for Not in use I C Clock GND VDIG VLCD I2C Data Table 5.1
2
Voltage ~3.2V 0V ~3.2V ~-3.8V ~3.2V
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ˇ If VLCD voltage is missing, proceed to section 5.3. ˇ If the I2C-DATA or the I2C-CLOCK voltages are missing, check VDIG (~3.2V). * If VDIG is incorrect, proceed to chapter 3 ("Doesn't start"-fault). * If VDIG is correct, measure the resistances of R619 (class A, 2.2 kohms), R620 (class A, 2.2 kohms), R668 (class A, 10 kohms) and R669 (class A, 10 kohms). Make sure the solderings at D600 pads 3 and 4 are correct. * If the resistances and the solderings are correct, replace D600 (class B).
Applies for KRC 114 279 (Seiko display): Measure the voltages at the display pads H622 (fig. 5.5):
Pad # 1 2 3 4 5 6
Used for Not in use I2C Clock GND VDIG VLCD I2C Data Table 5.2
Voltage ~3.2V 0V ~3.2V ~-2.8V ~3.2V
ˇ If VLCD is incorrect, proceed to section 5.3. ˇ If the I2C-DATA or the I2C-CLOCK voltages are missing, check VDIG (~3.2V). * If VDIG is incorrect, proceed to chapter 3 ("Doesn't start"-fault). * If VDIG is correct, measure the resistances of R619 (class A, 2.2 kohms), R620 (class A, 2.2 kohms), R668 (class A, 10 kohms) and R669 (class A, 10 kohms). Make sure the solderings at D600 pads 3 and 4 are correct. * If the resistances and the solderings are correct, replace D600 (class B).
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GA 628
Measure the voltages at the display pads H624 (fig. 5.10):
Pad # 1 2 3 4 5 6
Used for VLCD GND VDIG VDIG I2C Data I2C Clock Table 5.3
Voltage ~5.4V 0V ~3.2V ~3.2V ~3.2V ~3.2V
ˇ If VLCD is incorrect, proceed to section 5.3. ˇ If the I2C-DATA or the I2C-CLOCK voltages are missing, check VDIG (~3.2V). * If VDIG is incorrect, proceed to chapter 3 ("Doesn't start"-fault). * If VDIG is correct, measure the resistances of R619 (class A, 2.2 kohms), R620 (class A, 2.2 kohms), R678 (class A, 10 kohms) and R679 (class A, 10 kohms). Make sure the solderings at D600 pads 3 and 4 are correct. * If the resistances and the solderings are correct, replace D600 (class B).
If the problem isn't solved, send the phone to the next level.
Note: Fig. 5.4, 5.6 and 5.9 are not in this document.
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6 Charging.
6.1 Kind of charging fault.
Do a visual check of the battery screws and system connector. Replace if needed. Start the phone with a fully charged battery using the On/Off key. ˇ If it doesn't start, proceed to chapter 3 ("Doesn´t start"-fault). ˇ If the phone starts and indicates that it is charging without a charger connected proceed to section 6.2. ˇ If the phone doesn't indicate that it is charging, turn it off and connect a charger to the system connector. * If it starts, indicates that it is charging and lights the red top indicator then the phone is probably working correctly. To verify this, perform the test described in 6.1.1. * If the phone doesn't start, proceed to section 6.3 * If the phone starts and indicates that it is charging but doesn't charge, proceed to section 6.4. * If it starts and indicates that it is charging but the red top indicator isn't lit, proceed to chapter 9 ("Illumination"-fault).
6.1.1 Verifying the charging function.
Connect an ordinary battery to the phone. The voltage of the battery must be so high that you can start the phone with it. Otherwise the charging doesn't start immediately. Cut the cable from a charger and make a charging test cable. Connect the charging test cable to a power supply that shows the current consumption. Make sure that the DCIO pin is connected to the positive outlet of the power supply. As an alternative you can connect an ordinary battery charger in serial with an ampere meter. Set the power supply at 7.6V and a current limit of 700mA. Connect the charging test cable to the system connector of the phone and check the current consumption. ˇ There's nothing wrong with the charging function if the phone starts, indicates in the display that it's charging and switches between 700mA (500-800mA depending on charger model if utilising the alternative solution) and ~5mA with a few seconds interval.
Every time you repair a charging fault you have to verify the charging function as described above.
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6.2 Indicates charging without a charger.
Open the phone and check for liquid damages. The component side of the circuit board is shown in fig. 6.1.
Fig. 6.1 Give the board power and start it with the On/Off key. Check the voltages VDIG (~3.2V), VRAD (~3.8V, fig. 6.2) and the resistance in R703 (class A, ~0 ohms, fig. 6.3).
Fig. 6.2
Fig. 6.3 ˇ If any of the voltages are incorrect, proceed to chapter 3 ("Doesn´t start"-fault). ˇ If the voltages are correct, send the phone to the next level.
When you've repaired the fault you need to verify the charging function as described in section 6.1.1.
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6.3 Doesn't start when charger is inserted.
Open the phone and check for liquid damage. Check the pads at the system connector for oxidation and burn damages, especially on pad 10 (GND, fig. 6.4).
Fig. 6.4 Measure the resistance from DCIO to VBATT (~390 ohms, fig. 6.5).
Fig. 6.5 ˇ If the resistance is too low, replace V453 (class B). ˇ If it is too high, measure the resistance in R468 (class B, ~0.1 ohms) and R467 (Class A, ~390 ohms, all displayed in fig. 6.6). * If the measured values are correct, check the resistance from DCIO to R467 (~0 ohms, fig. 6.5, 6.6).
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* If the resistance is too high there is a foil damage and the phone is to be discarded.
Fig. 6.6 Check the resistance from GND (pad 10) to AGND (pad 4) at the system connector (~0 ohms, fig. 6.5). ˇ If the resistance is too high there is a foil damage and the phone is to be discarded. Give the board power and start it by grounding N451 pin 6 (fig. 6.6). ˇ If the phone starts the problem can't be solved at this level. ˇ If it doesn't start, replace V453 (class B, fig. 6.6). * If that doesn't help, replace V704 (class A, fig. 6.2).
When you've repaired the fault you need to verify the charging function as described in section 6.1.1.
6.4
Starts and indicates that it is charging but doesn't charge.
Open the phone and check for liquid damage. Check the system connector pads for oxidation and burn damages, especially pad 10 (GND, fig. 6.4). Measure the resistance from DCIO to VBATT (~390 ohms, fig. 6.5). ˇ If the resistance is too high, measure R468 (class B, ~0.1 ohms) and R467 (class A, ~390 ohms, both of the on fig. 6.6). * If the values are correct, check the resistance from DCIO to R467 (~0 ohms, fig. 6.5, 6.6). * If the resistance is too high there is a foil damage and the phone is to be discarded.
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Check the resistance from GND (pad 10) and AGND (pad 4, fig. 6.5) at the system connector pads (~0 ohms). ˇ If the resistance is too high there is a foil damage and the phone is to be discarded.
If the problem isn't solved, send the phone to the next level.
When you've repaired the fault you need to verify the charging function as described in section 6.1.1.
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7 SIM fault ("Insert card").
7.1 Definition of SIM-fault.
Insert a working SIM card and a fully charged battery into the phone. ˇ If the display says "Wrong card" or "Insert correct card" when you start the phone it means that the phone is SIM-locked and cannot be repaired at this level. ˇ If the display say "Phone lock" it means that the customer has locked the phone with a personal code. The phone will be unlocked in the reset part of the level 3 test. ˇ If the display says "PIN:" or "Enter PIN" it means that the SIM-card is locked with a personal code. ˇ Only if the display say "Insert card" there is a SIM fault.
7.2 Measuring VSIMPAD.
Measure the voltage at the system connector between pad 8 and 10 (~4.9V, fig. 7.1). ˇ If the voltage is too low or missing, proceed to section 7.3. ˇ If the voltage is correct, proceed to section 7.4.
Fig. 7.1
Fig. 7.2 shows the component side of the board and fig. 7.3 the front side.
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Fig. 7.2
Fig. 7.3
7.3 Voltage at VSIMPAD is missing.
Open the phone and check for liquid damages, especially below the SIM-card (J603, fig. 7.4).
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Fig. 7.4 Measure the resistance of R724 (class A, ~47 ohms, fig. 7.5).
Fig. 7.5 Give the circuit board power and start it up. Measure the input voltage at N705 pin 2 (~3.1V, fig. 7.4). ˇ If the voltage is too low or missing, check the VDIG voltage (~3.2V) at N702 pin 5 or at C600 (fig. 7.6).
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Fig. 7.6 * If VDIG is too low, measure the resistance to ground. * If it's more than 500 ohms, replace N702 (class A). * If it's less than 500 ohms, send to next level. * If VDIG is correct, measure the resistance of R716 (class A, ~4.7 ohms, fig. 7.5). * If the resistance is correct, check the resistance from R716 to N702 pin 5 (~0 ohms) and from R716 (opposite side) to N705 pin 2 (~0 ohms). * If any of the resistances are too high there is a foil damage and the phone should be discarded. * If the input voltage at N705 pin 2 is correct, measure the output voltage VSIMPAD (~5V) at N705 pin 3 (class A, fig. 7.4). * If the voltage is incorrect, replace N705. * If there is correct voltage, it could be foil damage between N705 pin 3 and R724 or between N705 pin 3 and V700 pin 1/V705 pin 1 (fig. 7.5, 7.4). If there is a foil damage the phone should be discarded.
7.4 There is voltage at VSIMPAD.
Check the SIM-card holder and make sure that the SIM-card contacts aren't dirty, bent or broken. Open the phone and check for liquid damage, especially below the SIM-card holder (J603, fig. 7.4).
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Make sure that the SIM-card holder is properly soldered. Make sure the SIM-card holder pads aren't loose (if they are, then the phone should be discarded due to foil damage) and that the board leads are intact. Measure the resistance of R704 (class A, ~100 kohms, fig. 7.5). Check the solderings at D600 pins 64, 72, 73, 74 and 75 (fig. 7.6). Measure the resistance of R600 (class A, ~33 ohms), R627 (class A, ~0 ohms) and R628 (class A, ~33 ohms, fig. 7.4). The resistor R627 is placed according to fig. 7.7 at revision R3A and above. Check the resistances from R600 to J603 pin 2 (~0 ohms) and from R628 to J603 pin 7 (~0 ohms). ˇ If any of them are too high there is a foil damage and the phone should be discarded.
Replace V700 (class A) and V609 (class A, fig. 7.5).
If the problem isn't solved, send the phone to the next level.
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8 Keyboard.
8.1 Kind of keyboard fault.
Insert a SIM card and a fully charged battery. Start the phone using the On/Off-key. ˇ If it doesn't start at all proceed to chapter 3 ("Doesn't start"-fault). ˇ If the phone (GH 688) consumes approximately 60mA (average, varies), the battery indicator blinks once or twice and then turns itself off proceed to section 8.2. Press all the keys (including the volume keys on the GH 688) to check which of the keys that are faulty. The following is the easiest way to check the keyboard: 1. Go to Menu/Setting/Key sound and choose "Click". 2. Press keys 1-9, *, 0, #. The phone should click and the display should show the corresponding symbol for each key pressed. Then press "Yes", "No", "Clr", "<" and ">". When pressing "Yes" the phone should try to place a call and when pressing "No" it should disconnect it. The "Clr" key should make the phone erase one or more symbols/numbers in the display when pressed. When pressing the keys "<" and ">" the phone should enter the menu for you to skim through. 3. Press the volume keys on the side of the phone (GH 688). The phone should click at every key pressed. ˇ If only the volume keys are faulty proceed to section 8.2 ˇ If one or more of the keyboard keys are faulty proceed to section 8.3 ˇ If the volume keys and one or more of the keyboard keys are faulty proceed to section 8.2 and then to 8.3.
8.2 Volume keys faulty.
Open the phone and check for liquid damage, especially around X820 (fig 8.1).
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Fig. 8.1 Clean the pads thoroughly.
Measure the resistance from V+ to GND. ˇ If the resistance is more than 25 kohms, replace the flex film for the volume keys. Assemble the phone and check if the volume keys work according to 8.1. * If not, replace D600 (class B, fig. 8.2). ˇ If the resistance is less than 25 kohms, replace D600 (class B, fig. 8.2).
Fig. 8.2
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8.3 One or more keys faulty.
Open the phone and check for liquid damage, especially around the keys that are faulty.
Clean the keyboard pads thoroughly and assemble the phone with a new keyboard. Check functionality according to 8.1.
If it didn't help, open the phone, give it power and start it up. Measure VDIG (~3.2V) on C600 (fig. 8.2). ˇ If VDIG is incorrect, proceed to chapter 3 ("Doesn´t start"-fault).
Fig. 8.3
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Fig. 8.4 ˇ If VDIG is correct, check if there is correct voltage (~3.2V) at marked sides on the pads of the faulty keys (GH 688 shown on fig. 8.5, GA 628 on fig. 8.6).
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GH 688
Fig. 8.5 Crossed out pads are not in use.
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GA 628
Fig. 8.6 Crossed out pads are not in use.
If there is no voltage at a whole row according to fig. 8.5/8.6 (for instance 1, 2, 3, Yes2), measure the resistance of that row's resistor (R630, R631, R632, R633 and R634, fig. 8.7). In this case the R630 resistor. All the resistors are of class A and should be ~100kohms.
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Fig. 8.7 ˇ If the resistance is correct, measure the resistance from C600 (fig. 8.2) to marked side of the resistors of the row (R630-R634, in this case R630, should be ~0 ohms) and from the other side of the resistor to the marked side of the keyboard pads (~0 ohms). * If any of the resistances are too high it means that there's a foil damage in the circuit board and the board is to be discarded. * If all of the resistances are correct, check the solderings at D600 pads 1 and 120-128. * If all of the solderings are correct, replace D600 (class B).
If there are voltage on only some of the pads on a row (for instance on pad 1 and 2 but not on pad 2, 4 or Yes2), there's a foil damage and the board is to be discarded. This can be verified through checking the resistance from marked side on a working pad to marked side of a non-working pad (~0 ohms). The foil damage is often caused by liquid damage.
If a column or a part of it is faulty, check the solderings of D600 pads 1 and 120128. ˇ If all the solderings are correct, replace D600 (class B).
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9 Illumination and buzzer.
9.1 Kind of fault.
Insert a dummy battery and a SIM card into the phone, press the On/Off-key and wait for the phone to get serv (instrument or net). ˇ If the phone doesn't beep when starting up, go to Menu/Setting/Ring level (Menu/Ring level at the GA 628) and try to raise the ring level to full. If there is no sound or if it is only faint proceed to section 9.2. ˇ If the illumination of the display doesn't light up at start, proceed to section 9.3. ˇ If the illumination of the keyboard doesn't light up at start proceed to section 9.4. ˇ If the top indicator of the phone doesn't start to blink green when getting serv, proceed to section 9.5. When the phone has gotten serv and the top indicator starts to blink green lower the battery voltage to 4.2V. The top indicator should start to blink red instead of green, the battery indicator should show an empty battery and the phone should warn with a beep. ˇ If the battery indicator doesn't show an empty battery, the top indicator doesn't blink red and the phone doesn't beep it means that the phone needs a battery calibration. ˇ If the battery indicator shows an empty battery, the phone beep but the top indicator doesn't blink, proceed to section 9.6. ˇ If the top indicator glows with both colors and the buzzer sounds faintly, proceed to section 9.7.
9.2 Buzzer sounds faintly or not at all.
Open the phone and check for liquid damage. Both sides of the circuit board are shown in fig. 9.1.
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Fig. 9.1a
Fig. 9.1b Make sure the buzzer, H600 (class A, fig. 9.1a) is properly soldered. ˇ If solderings are correct, replace the buzzer. Assemble the phone and test the buzzer again according to 9.1. * If the problem is solved, send the phone through the usual flow.
If the fault remains, disassemble the phone. Give the board power and start it up. Measure the voltage at H600 pad 1 (~3.3V, fig. 9.2).
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Fig. 9.2 ˇ If the voltage is missing at H600 pad 1, measure VRPAD (~3.8V) at V706 pad 2 (class A, fig. 9.2). * If the voltage at V706 pad 2 is missing, check if VRPAD is at C453 (fig. 9.3).
Fig. 9.3 * If VRPAD is incorrect or missing, proceed to chapter 3 ("Doesn´t start"fault). * If the voltage at C453 is correct, check the resistance from C453 and V706 pad 2 (~0 ohms).
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* If the resistance is too high there is a foil damage and the phone should be discarded. * If VRPAD at V706 pad 2 is correct, measure the resistance from VBATT to V706 pad 3 (~4.7 ohms, fig. 9.2) * If the resistance is too high, replace R652 (class A, fig. 9.2). * If the resistance is still too high after replacing R652 there is probably a foil damage somewhere between VBATT and marked side of R652 and the phone should be discarded. * If the resistance from VBATT to V706 pad 3 is correct, replace V706 (class A). Measure the resistance from H600 pad 2 to V606 pad 3 (10 ohms, fig. 9.2). ˇ If the resistance is too high replace R653 (class A, fig. 9.2). ˇ If the resistance is correct, check the soldering at D600 pad 91 (fig. 9.3). * If the soldering is correct, replace R651 (class A, fig. 9.3) and V606 (class A, fig. 9.2). * If that doesn't help, replace D600 (class B, fig. 9.3).
If the problem isn't solved, send the phone to the next level.
9.3 The illumination of the display is missing or faintly glowing.
Open the phone and check for liquid damage, especially at the marked area in fig. 9.4. Make sure all the LEDs (H651, H652, H653 and H654, all class A, fig. 9.1) are properly mounted and soldered.
Fig. 9.4 Give the board power and start it up. If a few, but not all of the LEDs aren't lit, replace them. ˇ If none of the LEDs are lit, measure the resistance of one of them.
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ˇ If the resistance is ~0 ohms at least one of them is shorted out. The simplest way of finding out which one of them is shorted out is by looking underneath the LED like in fig. 9.5. You can usually see dirt beneath the LED that is causing the short circuit. * If you can't see anything like that, remove the LEDs in the following order; H654, H651, H653 and finally H652. Measure the resistance after removing a LED. When the resistance increases it means that the faulty LED is removed. Mount new LEDs where you have removed the old ones.
Fig. 9.5 ˇ If the resistance of the LEDs is high, make sure that there is VBATT voltage at the marked side of the LEDs (fig. 9.1). * If VBATT is missing it most likely means that the phone is liquid damaged. If VBATT is correct, check that R612 (~0 ohms, class A), R610 (~27 ohms, class A) and R606 (~0 ohms, class A) are properly mounted and that they have the correct resistance (all in fig. 9.6).
Fig. 9.6
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Table 9.1 shows symptoms when the resistance of the resistors are incorrect.
Missing or broken R606 R611 R612 R610
H651H654 Faintly glowing Lit Not lit Not lit Table 9.1
H655H660 Not lit Not lit Faintly glowing Lit
ˇ If none of the LEDs H651-H654/H655-H660 (fig. 9.1 and 9.6) are lit, measure the voltage at the marked of R607 (~3.1V, fig. 9.3). Before you measure you have to press a key on the phone to make the processor set the LED3K signal high for about 10 seconds. * If the voltage is missing, check the soldering at D600 pin 92 (fig. 9.3). * If the soldering is correct, replace D600 (class B). * If the voltage is correct, replace R607 (class A).
9.4
The keyboardillumination is missing or faintly glowing.
Open the phone and check for liquid damage, especially at marked area in fig. 9.4. Make sure that all the LEDs H655-H660 (class A, fig. 9.6) are physically intact, correctly mounted and soldered. Give the board power and start it up. If a few but not all of the LEDs are lit, replace them. ˇ If none of the LEDs are lit, make sure that the VBATT voltage is at marked side of the LEDs. * If VBATT is missing it most likely means that the phone is liquid damaged. * If VBATT is correct, check that R612 (~0 ohms, class A), R611 (~47 ohms, class A), R610 (~27 ohms, class A) and R606 (~0 ohms, class A) are properly mounted and that they have the correct resistance (all in fig. 9.6). Table 1 shows symptoms when the resistance of the resistors are incorrect. ˇ If none of the LEDs H651-H654/H655-H660 (fig. 9.1 and 9.6) are lit, measure the voltage at the marked side of R607 (~3.1V, fig. 9.3). Before you measure you have to press a key on the phone to make the processor set the LED3K signal high for about 10 seconds. * If the voltage is missing, check the soldering at D600 pin 92 (fig. 9.3). * If the soldering is correct, replace D600 (class B). * If the voltage is correct, replace R607 (class A).
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9.5 Green LED at the topindicator doesn't work.
Open the phone and check for liquid damage. The front side of the board is shown in fig. 9.1. Make sure the double LED H650 (class A, fig. 9.1) is correctly soldered. ˇ If the solderings are correct, give the board power and start it up. Measure the voltage at H600 pad 1 (~3.3V, fig. 9.2). ˇ If the voltage is missing at H600 pad 1, measure VRPAD (~3.8V) at V706 pad 2 (class A, fig. 9.2). * If the voltage at V706 pad 2 is missing, check if VRPAD is at C453 (fig. 9.3). * If VRPAD is incorrect or missing, proceed to chapter 3 ("Doesn´t start"fault). * If the voltage at C453 is correct, check the resistance from C453 and V706 pad 2 (~0 ohms). * If the resistance is too high there is a foil damage and the phone should be discarded. * If the VRPAD voltage at V706 pad 2 is correct, measure the resistance from VBATT to V706 pad 3 (~4.7 ohms, fig. 9.2). * If the resistance is too high, replace R652 (class A, fig. 9.2). * If the resistance still is too high after replacing R652 there's probably a foil damage somewhere between VBATT and marked side of R652 and the phone should be discarded. * If the resistance from VBATT to V706 pad 3 is correct, replace V706 (class A). Check the soldering at D600 pad 94.
If the problem isn't solved, send the phone to the next level.
9.6 Red LED at the topindicator doesn't work.
Open the phone and check for liquid damage. The front side of the board is shown in fig. 9.1. Make sure the double LED H650 (class A, fig. 9.1) is correctly soldered. ˇ If the solderings are correct, give the board power and start it up. Measure the voltage at H600 pad 1 (~3.3V, fig. 9.2). ˇ If the voltage is missing at H600 pad 1, measure VRPAD (~3.8V) at V706 pad 2 (class A, fig. 9.2). * If the voltage at V706 pad 2 is missing, check if VRPAD is at C453 (fig. 9.3).
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* If VRPAD is incorrect or missing, proceed to chapter 3 ("Doesn´t start"fault). * If the voltage at C453 is correct, check the resistance from C453 and V706 pad 2 (~0 ohms). * If the resistance is too high there is a foil damage and the phone should be discarded. * If VRPAD at V706 pad 2 is correct, measure the resistance from VBATT to V706 pad 3 (~4.7 ohms, fig. 9.2). * If the resistance is too high, replace R652 (class A, fig. 9.2). * If the resistance is still too high after replacing R652 there is probably a foil damage somewhere between VBATT and marked side of R652 and the phone should be discarded. * If the resistance from VBATT to V706 pad 3 is correct, replace V706 (class A).
Check the soldering at D600 pad 93. If the problem isn't solved, send the phone to the next level.
9.7 Both LEDs at the top indicator glows faintly and the buzzer sounds faintly.
Open the phone and check for liquid damage. Give the board power and start it up. Measure VRPAD (~3.8V) at v706 pin 2 (class A, fig. 9.2). ˇ If VRPAD is correct, replace V706 (class A). * If that doesn't help replace R652 (class A). ˇ If the voltage at V706 pin 2 is missing, check if there is voltage at C453 (~3.8V, fig. 9.3). * If it's incorrect or missing, proceed to chapter 3 ("Doesn´t start"-fault). * If the voltage at C453 is correct, check the resistance from C453 to V706 pad 2 (~0 ohms). *If the resistance is too high there is a foil damage and the phone should be discarded.
If the problem isn't solved, send the phone to the next level.
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10 RTC
10.1 Find fault.
Insert a SIM card and a fully charged battery into the phone and start it up. Set the correct time. Remove the battery and reinsert it after a minute. ˇ If the time says 00:00 proceed to section 10.2. Compare to the correct time. ˇ If the clock is speeding or is halted proceed to section 10.3
The component side of the circuit board is shown in fig. 10.1.
Fig. 10.1
10.2 The time says 00:00 after removed and reinserted battery.
Open the phone and check if the backup capacitor C720 (class A, fig. 1.2) is correctly soldered.
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