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Repair tips

Electronic appliance repair tips database - TV (LCD,TFT,Plasma,Digital), Monitor, VCR, DVD recorder and player, Digital camera, Audio equipment, Microwave ovens, Phone systems, Computer repair

MakeModelProblemSolutionDate
Found: 4551
PhilipsGR1AXPic & sound int blank out esp on chan changeIC7470 TDA2579B/N1 timebase chip14-09-04
PhilipsGR1AXPicture fails for a short time.Diode 6542 (BYD33D) dry joint. 14-09-04

PhilipsGR1AXPoor H.T regulation and intermittent over voltage tripping.D6629 (BZX79-B6V2; 4822 130 34167). 14-09-04
PhilipsGR1AXpoor line syncC2501 ( 10uF )14-09-04
PhilipsGR1AXPoor reproduction of copy protected tapesIt is possible that reproduction of some VCR tapes will be adversely affected by anti copy signals which are recorded on the video tape during the sync. period. A significant improvement can be achieved by applying the following modification: Position 14-09-04
PhilipsGR1AXPower supply does not oscillate.Check C2613 (33nF; 4822 121 42489) on leakage. 14-09-04
PhilipsGR1AXPower supply faultfindingPower supply faultfinding ------------------------- The power supply in the GR1-AX delivers approximately 33 watts on the +95V line to run the set. Clearly the practice of using a 60 watt 240V lamp as a load during fault finding cannot be applied in this14-09-04
PhilipsGR1AXPower supply not working.Check D6610 for short-circuit (BZX79-C10; 4822 130 61219). 14-09-04
PhilipsGR1AXPower supply tripping.95 volt line pulsing. Check/replace R3614 - 6.8k (4822 053 11682) in chopper driver coupling circuit. 14-09-04
PhilipsGR1AXProduction change to +9V supplyProduction change to +9V supply ------------------------------- A production change has been introduced to the +9 volt supply. Receivers concerned are factory coded SV008921 and higher. Position Old New Code No. 3100 14-09-04
PhilipsGR1AXProduction change to line driveProduction change to line drive ------------------------------- A production change has been introduced to the line drive circuit. Receivers affected are factory coded SV008921 and higher. Reason: To improve the function of the line drive circuit. Pos14-09-04
PhilipsGR1AXProgramme tuning difficulty, stations shifted on the tuning bar.Stations appearing to the right of the usual position on the tuning bar although the bar itself scans normally. Higher channels may not be accesssible at all. Investigation has shown that although the 33V supply and the pulse drive from pin 1 of IC7700 14-09-04
PhilipsGR1AXPrograms and PP-settings cannot be changedIt may happen that when switching on from standby the set comes on in "store lock" mode (sometimes called "hotel mode"). In this mode stored settings for programme selection and personal preference cannot be changed (see operating instructions for leavin14-09-04
PhilipsGR1AXReluctant start from cold - no 95v HTOK if set HT pot reduced - Zener 6638 BZX79-B36 in HT sensing leaky14-09-04
PhilipsGR1AXRepair-tip power-supplyRepair-tip power-supply ----------------------- It is not allowed to connect a measuring probe to the gate of MOS-FET transistors TS7610 because the set will not function well, or the MOS-FET might be damaged.14-09-04
PhilipsGR1AXRepeat failure of line output transistor item 7528After fitting a new transistor Type 2SC3795B Pt. No.4822 130 60676 check soldered connections to socket M3 14-09-04
PhilipsGR1AXReplacing the EAROMReplacing the EAROM ------------------- The memory IC IC7785, X2402 has been replaced by ST24C02CP (4822 310 31886). Together with the ST24C02CP change-over, the 5 volt supply has to be adapted: L5786 has to be connected between pin 8 of IC7785 and R37914-09-04
PhilipsGR1AXSearch jumps on UHF.Check/replace R3788 (2M2; 4822 116 81682). 14-09-04
PhilipsGR1AXSearch tune won't stop & sound slow to come on when chan changedIdent signal from micro perm low - Tr7046 BC558 s/c14-09-04
PhilipsGR1AXService information correction.Service information correction. ------------------------------- In Service Information GR1-AX 91.02, 4822 727 18934 (GB), chapter 7 the replacement code for the U943/PHONO is not correct. This should be 4822 210 10452.14-09-04
PhilipsGR1AXServicing the Philips GR1-AX ChassisSee TV Mag May 199414-09-04
PhilipsGR1AXSet dead due to action of over-voltage-protection circuit.If thyristor 6641 is disconnected, the set starts up. Disconnect T7100 and see if the set comes on, if so suspect T7100 (4822 130 40947) or a fault on the 9 volt rail, probably an audio fault. If the audio output IC7103 is disconnected, the set starts 14-09-04

PhilipsGR1AXSet fails to start-up from standby mode, or at cold temperature.Change C2058 from 33 uF to 47 uF 100V (4822 124 42085). REMARKS : The cure is applicable for sets produced in week 9041-9047. 14-09-04
PhilipsGR1AXSet goes accidentally into hotel mode.The hotel mode will be activated if the set is on program 38 and if "store" and "program +" are pressed simultaneously. However this can also happen when "program -" and "program +" are pressed instead. To block this possibility: interrupt the copper trac14-09-04
PhilipsGR1AXSet goes into Stand-byCheck/replace C2631 (22nF; 4822 122 40606) 14-09-04
PhilipsGR1AXSet is intermittently not coming on, especially from cold.High Tension coming up to normal voltage but there is no line drive. Check start up pulse to line osc IC - pin 11 of IC 7020. If OK, check to see if line drive appears for an instant at switch on, on pin 26. If so, check on base of line output transist14-09-04
PhilipsGR1AXSet switches to stand-byCheck/replace C2631 (22nF; 4822 122 40606) 14-09-04
PhilipsGR1AXSet will not come out of standbyCheck/replace the EPROM, IC7785 (ST24C02CP; 4822 209 62098) 14-09-04
PhilipsGR1AXShuts once in a while and goes to stand-by.Check C2631 (22nF; 4822 122 30103) on leakage. 14-09-04
PhilipsGR1AXSlow start up fropm cold with no OSDTR7765 (BC548) s/c between B-E, C2523-68uF14-09-04
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