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5 Troubleshooting
5-1 Parts Level Troubleshooting
Notes: 1. If a picture does not appear, fully rotate the brightness and contrast controls clockwise and reinspect. 2. Check the following circuits. · No raster appears: Power circuit, Horizontal output circuit, H/V control circuit, and H/V output circuit. · High voltage develops but no raster appears: Video output circuits. · High voltage does not develop: Horizontal output circuits.
5-1-1 No Power Supply
Check and replace FG601, D601, IC661, IC662. Yes
WAVEFORMS
1 544 V (IC601, #1)
Repeating start?
Check and replace D601, D604, D663, Q632, and Q664.
No
CH1 P-P = 544 V CH1 RMS = 332.4 V
1
IC601 Pin 1 waveform is right?
No
Check and replace IC601, IC602, IC604.
Yes IC602 and IC604 are right? Yes Normal operation No Replace Main board. No Replace parts and verify voltages.
Yes Verify voltages. Yes Done.
PG17**/PG19**/PG21**
5-1
5 Troubleshooting
5-1-2 DPMS Failure
Check signal source H/V sync video level.
Make No H/V sync (power off mode)
LED blinks
No
Check IC201 Pin 39.
Yes +12 V line off No Check IC201 Pin 9.
Yes Q632 Base driving voltage exists? No Check IC201 Pin 10. Check and replace Q632.
Yes Done
5-2
PG17**/PG19**/PG21**
5 Troubleshooting
5-1-3 H_Deflection Failure
IC402 Pin 6 waveform is right? No 1. Check R401, +12 V line. 2. Check IC402 Pins 6~5, 7~6. 3. Replace IC402.
WAVEFORMS
2 10.96 V (IC402, #6)
2
Yes
3
Q403 source waveform is right? Yes
No
Check D407, D408, Q403, R436 and R438, +210 V line.
CH1 P-P = 10.96 V CH1 RMS = 6.180 V
3 230 V (Q405, Source)
4
5
Q404 gate, drain waveforms are right? Yes
No
Check Q404, R415. Check +25 V line.
CH1 P-P = 230 V
CH1 RMS = 150.1 V
6
7
Q405 base, collector waveforms are right? Yes IC261 Pin 4 is high?
No
Check and replace D410 and Q405. Check DY connector connection.
4 11.6 V (Q404, Gate)
No
Replace IC261.
CH1 P-P = 11.6 V
CH1 RMS = 6.944 V
5 54 V (Q404, Drain)
Yes Check some parts around Q263.
CH1 P-P = 54 V
CH1 RMS = 22.44 V
8
IC261 Pin 26 waveform is right? Yes Check some parts around Q261 and Q262.
No
6 18.6 V (Q405, Base)
Check some parts around IC261.
CH1 P-P = 55.2 V
CH1 RMS = 9.52 V
8 12.08 V (IC261, #26)
7 1.216 kV (Q405, Collector)
CH1 P-P = 12.08 V
CH1 RMS = 7.396 V
CH1 P-P = 1.216 kV CH1 RMS = 316 V
PG17**/PG19**/PG21**
5-3
5 Troubleshooting
5-1-4 S Correction Failure
Check S1 ~ S5 signal.
S1~S5 signals are right at each frequency block? Yes Check and replace C430, C431, C433, C434, C435, C437 C441, C453, C454, C455, C456, C457, Q409~Q413, Q451~Q455, Q456~Q460 .
No
Check and replace IC201.
5-1-5 H_Lin. Failure
IC201 Pin 21 voltage varies with different H_Lin. DAC values? Yes IC403 Pin 7, 8 voltage varies with different H_Lin. DAC values? Yes Check L403. No Check +12 V line. Check some parts around IC403. No
Replace IC201.
5-1-6 Invariable H_Size
IC261 Pin 28 voltage varies with different H_Size DAC values? Yes IC401 Pin 6 output duty varies with different H_Size DAC values? No Check some parts around IC261 Pin 28, IC401. No
Check and replace IC261.
5-4
PG17**/PG19**/PG21**
5 Troubleshooting
5-1-7 Abnormal H_Size
No
WAVEFORMS
Check and replace T402.
9 29.8 V (T402, #8)
9
T402 Pin 8 waveform is right?
Yes Check some parts around D415, IC261 Pin 28, IC402 Pin 2 and IC201 Pin20.
CH1 P-P = 29.8 V CH1 RMS = 7.14 V
5-1-8 Side Pin or Trap Failure
No
IC261 Pin 24 output exists?
Check and replace IC261.
Yes Check and replace IC402. Check some parts IC402 Pin 2 and IC261 Pin 24.
5-1-9 Para. or Pin Balance Failure
IC261 Pin 24 output varies with different DAC values? No Replace IC261.
PG17**/PG19**/PG21**
5-5
5 Troubleshooting
5-1-10 Tilt Failure
Check tilt connector connection
IC201 Pin 23 output duty varies with different DAC values? Yes IC403 Pin 10, 11 output varies with different DAC values? Yes Check and replace CRT.
No
Check and replace IC201.
No
Check and replace IC403.
5-1-11 V Deflection Failure
No
±14 V line is on?
Refer to 5-1-1 No Power Supply
Yes IC261 Pin 23 output exists? No Check and replace IC261.
Yes IC301 Pin 1 input exists? No Check R276 and R304.
Yes IC301 Pin 6 output exists? No Check and replace some parts around IC301.
Yes Check V DY connector connection.
5-6
PG17**/PG19**/PG21**
5 Troubleshooting
5-1-12 V Size or Pos. Variation Failure
IC261 Pin 23 output varies with different DAC values? Yes Check and replace IC261 and IC301. No
Check some parts around IC301. Check bias voltage.
5-1-13 High Voltage Failure
Q524 gate driving pulse exist?
No
Check +12 V line. Check and replace Q521, Q522, Q523, Q524 and IC501.
Yes Done
PG17**/PG19**/PG21**
5-7
5 Troubleshooting
5-1-14 ABL Failure
Input full white pattern to monitor.
IC101 (17": IC104, Pin12) Pin 15 input exists and varies with different patterns? No Check CN102.
Yes
Check and replace IC101 (17":IC104).
T501 Pin 8 output exists?
No
Check and replace T501.
Yes IC103 (17": IC04) Pin 16 output exists and varies with different patterns? Yes Check and replace Q101, Q102 and +12 V line. No Check and replace IC103 (17": IC04).
5-1-15 Dynamic Focus Failure
IC261 Pins 18 and 15 output are right? Yes Some parts around Q551, Q552, Q553 and Q554 are right? Yes
14
No
WAVEFORMS
Check and replace IC261.
13 2.20 V (IC251, #15)
13
No
Replace failed part.
CH1 P-P = 2.20 V CH1 RMS = 2.776 V
14 580 V (T551, #1)
Some parts around T502 are right?
No
Replace failed part.
Yes
CH1 P-P = 580 V CH1 RMS = 278.2 V
Check the connection between FBT Pin 13, CRT Socket PCB.
5-8
PG17**/PG19**/PG21**
5 Troubleshooting
5-1-16 No Video
Check signal cable and connection.
IC101 Pins 2, 6 and 11 (17": IC104, Pin 5, 8, 10) inputs are right? Yes IC101 Pins 29, 32 and 35 (17": IC104, Pin 25, 28, 30) outputs are right? Yes IC102 Pins 4, 6 and 14 (17": IC105, Pin 1, 3, 5) outputs are right? Yes Cathode DC levels are right?
No
Check CN101 and BNC B'D IC1.
No
Check I2C bus and +12 V line.
No
Check +12 V line. Check and replace IC102 (17": IC105).
No
Check +80 V line. Check and replace IC101 and IC104 (17": IC104).
Yes G2 voltage is right? No Check G2 wire, CRT Socket board, and FBT.
Yes Change CRT.
Done.
PG17**/PG19**/PG21**
5-9
5 Troubleshooting
5-1-17 Micom Failure
No
WAVEFORMS
Check IC606.
15 3.42 V (IC201, #33)
IC201 Pin 11 input is right?
Yes
15
IC201 Pins 13 and 14 inputs are right? 16 Yes IC201 Pin 18 input is right?
No
Check X201, C204 and C205.
CH1 P-P = 3.42 V CH1 RMS = 2.500 V
16 3.16 V (IC201, #32)
No
Check IC202.
Yes All in/output values are right? No Replace IC201.
CH1 P-P = 3.16 V
CH1 RMS = 2.560 V
Yes Done
5-10
PG17**/PG19**/PG21**
5 Troubleshooting
5-1-18 OSD Failure
Check CN102 and connector Ass'y.
IC103 (17": IC04) Pin 17 input is right? Yes IC103 (17": IC04) Pin 6 input is right? Yes IC103 (17": IC04) Pins 7 and 8 inputs are right? Yes IC103 (17": IC04) Pins 20, 21 and 22 outputs are right? (17" only) Yes IC101 (17": IC104) Pins 4, 9 and 13 inputs are right? Yes Check and replace IC101 (17": IC104) .
No
Check and replace D302 and Q301.
No
Check and replace Q104 (17": Q103) .
No
Check IC201 Pins 41 and 42.
No
Check and replace IC103 (17": IC04) .
No
Check and replace QB51, QG51 and QR51.
Done
PG17**/PG19**/PG21**
5-11
5 Troubleshooting
5-1-19 User Control Failure
Check connector Ass'y.
IC201 Pins 35 and 36 inputs are right at each function. Yes Check and replace IC201.
No
Check and replace function key.
Done
5-1-20 Degaussing Failure
Check degaussing connector.
RL601 operation is right?
Yes
Check D-Coil, TH601.
No Q630 base input is right? Yes Check and replace Q630.
No IC201 Pin 40 output is right? No Check and replace IC201. Check user function key.
Yes R217 and R630 are right? No Replace R217 and R630.
Yes Done
5-12
PG17**/PG19**/PG21**
5 Troubleshooting
5-2 General Troubleshooting
5-2-1 No Picture
Yes
LED blinks?
5-2-2 Shut down
No LED is green color? No LED is Amber color? Yes Check signal cable.
Yes Check G2 voltage, high voltage, R, G, B cathode voltage.
No After restart monitor LED don't come on, repair power circuit.
5-2-2 Shut Down
Blinking LED's?
No
Check power supply.
Yes Scan failure Yes Check horizontal, vertical deflection system and check power supply secondary voltages.
No High voltage failure? Yes Check high voltage system.
No Video failure? Yes Check Video board.
No Check and replace IC201.
Done
PG17**/PG19**/PG21**
5-13
5 Troubleshooting
5-2-3 Missing Color
Are proper Video levels on CN101 (D-Sub) Pins 1, 2 and 3, R-BNC, G-BNC and B-BNC. Yes Are proper AC voltage on all cathodes? Yes Are proper DC voltage on all cathodes? Yes Is G2 voltage right?
No
Check signal generator and cathode.
No
Refer to 5-1-16 No Video.
No
Check IC104 (17": IC104 Pins 19, 20, and 21) Pins 10, 11 and 12. Check QB02, QB03, QG02, QG03 QR02 and QR03.
No
Check G2 wire, G2 control, volume and FBT.
Yes Change the CRT.
Done
5-14
PG17**/PG19**/PG21**
5 Troubleshooting
5-2-4 Visible Retrace
Check white balance adjustment.
Is G2 voltage right?
No
Check G2 control volume and FBT.
Yes Is blank pulse on Pin 27 of IC101 (17": Pin 23 of IC104) on Video board? Yes Is blank pedestal on Pins 29, 32 and 35 of IC101 (17": 25, 28, 30 of IC104) Yes Is V_FLB pulse on Pin 17 of IC103 (17": IC04)? Yes Is blank pedestal on all cathodes? No Check Pins 24, 25 and 26 of IC101 (17": 19, 20, 21 of IC104). Check QB02, QB03, QG02, QG03, QR02 and QR03. No Check Q301. No Check IC101 (17": IC104) and related components. No Check CN102, Q104 (17": Q103).
Yes Done
PG17**/PG19**/PG21**
5-15
5 Troubleshooting
5-2-5 Unsynchronized Image
Check input signals Pins 1, 2 and 3 of D-SUB connector.
Are signals right?
No
Check Video cable.
Yes Signals at Pins 1, 3 and 5 of IC1 are right? Yes Signals at CN201 Pins 6, 9 and CN102 Pin 6 are right? Yes Check circuits on Main board. (IC201 and IC261) No Check wire dressing and connections. No Replace IC1.
Done
5-16
PG17**/PG19**/PG21**
5 Troubleshooting
5-2-6 Misconvergence
Try readjusting convergence.
Is the convergence now within spec? No Readjust convergence.
Yes
Done
Is the convergence now within spec? No Change CRT and readjust convergence.
Yes
Done
Done
PG17**/PG19**/PG21**
5-17
5 Troubleshooting
5-2-7 Poor Focus
Adjust focus VR.
Improved focus?
Yes
Aging monitor and check for focus change.
No Check focus leads from FBT to CRT Socket.
Check the CRT Socket.
Is dynamic focus circuit right?
No
Refer to 5-1-15 Dynamic Focus Failure.
Yes Replace the CRT and verify focus.
5-2-8 Purity Failure
Degaussing
Purity is right?
Yes
Done
No Degaussing circuit is right? No Refer to 5-1-20 Degaussing Failure.
Yes Replace CRT and verify purity.
5-18
PG17**/PG19**/PG21**