JVC  TSS log 
Brand Model Chassis Keyword Symptom Cure
JVC AV27770   Audio JVC AV27770. Noisy audio on Channel 15 when other TV's in the house are have no trouble on the same channel. SAP and Mono sound fine Just stereo has a buzz This unit is a stereo TV. The other TV's that you were using are not stereo compatible. The problem can only be heard in the Stereo mode. There is a corrupted 32KHZ sub-carrier for the L-R information. As long as the L-R data is corrupted the stereo will also be corrupted. Tech will need to bring out a test set that will support SAP stereo to prove to customer the symptom is caused by the signal source.
JVC AV32820 FK Audio JVC AV32820. Unit has noisy audio on channel 5 only. Channel is converted from channel 18 to channel 5 through a translator within a small community CATV system. All other channels are fine. This unit is an MTS stereo television. Tech needs to enter the tech mode and gain access to the Picture mode and set the IF VCO from 64 to 56. Now the unit is working 
JVC AV32920 GW Audio AV32920 serial 13396208. Unit has a sweep audio tone in the audio that is only on channel 14. The audio is loud enough to be heard very clear. The is a by product of a signal used by the CATV co.  JVC  instructed us to try and move the IF VCO from 63 to 45 where it does minimize the this tone but it will not totally eliminate it.  It is called the Sniffer Tone. It transmits on 115.275 MHz. It is used by the CATV co. to check there system for R.F. leakage outside their system. I instructed tech to adjust the 4.5 MHz coil which is the sound take off coil until the beeping tone disappears then stop. Then check all the other channels to see if they are negatively effected. Nothing was effected. I had the tech leave it this way and the beeping did not occur again.
JVC AV36980 GK3 Audio Audio has an inconsistent level during the telecast of a movie channel or network Suggested the tech try to increase the Input level of the composite audio signal. By entering the tech service mode and raising the level of item 5= input level from 37 to 43. If the television cannot always detect the stereo sub carrier it will drop stereo reception and revert to mono reception.
JVC AV36980 GK3 Audio AV36980 Audio has an inconsistent level during the telecast of a movie channel or network Suggested the tech try to increase the Input level of the composite audio signal. By entering the tech service mode and raising the level of item 5= input level from 37 to 43. If the television cannot always detect the stereo sub carrier it will drop stereo reception and revert to mono reception.
JVC C2010   BUZZ C2010 Unit has an 60 Hz buzz in the chassis from the power on relay. Unit will turn on but the buzz is very loud, but the set does turn on and have a picture. The relay coil is powered from a half wave rectifier and filter capacitor C791. When measuring the ripple on this low pass filter with a oscilloscope the ripple exceeds 90 volts peak to peak. C791  a 4.7 mfd@250 is open
JVC AV27D200 GR BUZZ in cabinet AV27D200 Unit has a mechanical vibration in the audio that occurs on certain frequencies. Tech needs to bring with him a variable audio frequency generator and vinyle tape or friction tape. The generator will allow the tech to supply the offending frequency into the television without waiting for the broadcast audio source to send it. The tech will be able to quickly identify  the source of the mechanical vibration due to its mechanacal resonace. Once identified the area is inspected for for items that may be mechanically touching or nearly touching. The tape is used to fill the gap between the touching or nearly touching parts of the cabinet to fron bezel, or CRT to bezel, OR speaket to cabinet .... etc.
JVC AV27D100   Cabinet Vibration Unit has a mechanical vibration in the audio that occurs on certain frequencies. Tech needs to bring with him a variable audio frequency generator and vinyl tape or friction tape. The generator will allow the tech to supply the offending frequency into the television without waiting for the broadcast audio source to send it. The tech will be able to quickly identify the source of the mechanical vibration due to its mechanical resonance. Once identified the area is inspected for  items that may be mechanically touching or nearly touching. The tape is used to fill the gap between the touching or nearly touching parts of the cabinet to front bezel, or CRT to bezel, OR speaker to cabinet .... etc.
JVC AV32920 GW Chroma AV32920 serial # 13338318. Unit has no chroma. The jungle IC was replace without effecting the performance of the unit. Set has normal brightness and sound. I had tech start at the beginning again and simply confirm te "MUST HAVES" This was the three B+  sources to the Jungle IC. This chip ha 3 independent B+ sources. The first source voltage was the VCJ source was only 6.7 volts. It is supposed to be 9 volts. Its source voltage is IC101 an LA7809 three legged regulator. Input B= was at 15 vdc but he output was at 6.9 vdc. It was not overly warm. Suggest the tech replace the regulator before going any further. Problem was a defective IC101
JVC AV32920 GW CHROMA Unit has no chroma. The jungle IC was replaced without effecting the performance of the unit. Set has normal brightness and sound. I had tech start at the beginning again and simply confirm the "MUST HAVE" This was the three B+  sources to the Jungle IC. This chip has 3 independent B+ sources. The first source voltage was the VCJ source was only 6.7 volts. It is supposed to be 9 volts. Its source voltage is IC101 an LA7809 three legged regulator. Input B was at 15 vdc but the output was at 6.9 vdc. It was not overly warm. Suggest the tech replace the regulator before going any further. Problem was a defective IC101.
JVC NV55BX4 PU chroma NV55BX4 Unit has incorrect chroma demodulation. When the color bars are put up on the screen the set does not have Blue. Without blue this set cannot develop correct color demodulation. Tech needs to replace the aspect ratio converter module. There is no B-y signal from this module. Note: All modules in this unit are replaceable. The technician should not attempt to repair the module.
JVC AV27710   Chroma missing AV27710 Unit has no chroma. No color. The 9 volt source is running at 8.9 vdc. Chroma is getting to the IC210(45). When checking the crystal we find it is on frequency, but not phase locked to the in coming chroma. Measuring IC201(11) we have ripple at the horizontal, and 3khz rate.  Unit has a leaky C407 a .47 mfd at 50 volts.
JVC AV32720 GKII Chroma missing Unit has excellent black and white picture but no color in tuner or video input mode. Measuring the B+ at IC201(46) we find the voltage only 7.2 volts. It should be 9 volts. Checking the output of IC101(out) was also 7.2 volts. Unit has defective IC101 Part # BA17809T.
JVC AV32720 GKII clock Clock will loose or gain time, or not advance at all When checking the clock signal at the Micro IC701(11) we have no 60 hz pulses. They must be at 5 volts peak to peak. Following this signal from the source, PC902, the photo coupler, we found that we had a solid 60 Hz input but "0 volts" at collector of the PC902. At times we have spikes and noise. Other times we have nothing at all. Replacing PC902 corrected the trouble. Part# TLP621.
JVC NV55BX4 PU CONVERGENCE NV55BX4 Unit has sever convergence error. IC902 NM7812 has only 7 volts on the output that causes it to over heat. IC905(out) has "0" volts on it.  This is directly connected to IC101 the convergence wave form generator.  I asked tech to  disconnect  the b+ from the IC101(40) and see if the -5 volts return to normal. After close checking the IC905 shows that it has a NMN7812 in place of a NMN7905. This will not work the IC was substituted with a positive 12 volt regulator  instead of a negative 5 volt regulator.
JVC NV55BX4 PU CONVERGENCE Unit has severe convergence error. IC902 NM7812 has only 7 volts on the output that causes it to over heat. IC905(out) has "0" volts on it.  This is directly connected to IC101 the convergence wave form generator.  I asked tech to disconnect the B+ from the IC101(40) and see if the -5 volts return to normal. After checking, the IC905 shows that it has a NMN7812 in place of a NMN7905. This will not work the IC was substituted with a positive 12 volt regulator instead of a negative 5 volt regulator.
JVC AV27950   Dead AV27950 Ser 15386629 . Unit is dead. Customer explained just before the set went dead the set has a bright flash in the raster Unit has no stand by supplies. No secondary B+ from SWITCH MODE POWER SUPPLY
JVC AV27D303 FE Dead Unit is basically dead. No standby voltages. Closer inspection finds that IC901 in power supply is blown out and the main fuse is open. Recommend that F901 a 5 amp fuse and IC901 STR-G5624/F8 but check and or replace D908 a 15 volt regulator before power up unit again.
JVC AV32920 GW Dead JVC AV32920 Unit is dead. Unit will not turn on. Checking the stand by power supply found the Switch mode power Supply is not running. Voltage at IC901(4) is zero volts. However the half wave rectifier D902 has 80 volts on the cathode. R903 a 33K1/2 watt resistor is open. 
JVC AV32D200   Dead Television will not turn on. When checking the B+ on the CPU and EEPROM  I found it was normal.  At the instant that power was applied the Data and clock on the EEPROM  was missing. Both lines stayed low during reset, but rose to 5 volts after 3 secinds The Microprocessor has normal reset normal A.C. clock to pin 11. But the 12 mhz crystal at pin 62 & 63  is not running. Unit has defective crystal.
JVC AV35890 GK3 Dead AV35890 The set has a line surge from the A.C. power company. It caused the main 5 amp line fuse to blow. Ever since then the clock has not been keeping the correct time. When the clock is set the time will increment erratically. It may loose 2 hours in 1 day or loose 10 another day. It is not consistent. Tech needs to check the condition of PC902(4) This is a photo optic isolator that is connected to the A.C. line and is used to couple the A.C. pulses to IC701(11) for the AC clock reference. It is probable that the same surge that caused the main fuse to blow caused some damage to PC902 causing this trouble.  It looks as though there is supposed to be a 14 volt pp signal at PC902(4). It will be inverted by digital transistor Q742(CoL) where it should be 5 volt peak to peak. It is this point that the signal should be clean going to IC701(11)  It appears the signal was very clean up to this point. The trouvbble was IC701
JVC AV36950 GV Dead Check the secondary of the power supply we found there was no secondary voltages on D923 or D922, but there was B+ at D925, but it was slowly dropping. Closer observation shows that C926 a 1000mfd@35vdc was leaky. Replacement of this device corrected the symptom.
JVC AV36950 GV Dead Unit does not turn on. When checking the secondary of T901 ands the rectifier diodes D922, or D923 the voltage never pops up as soon as the TV is plugged in. IC901(4) cycles from 8 to 15 volts DC Checking the resistances to ground on the secondaries of T901 finds no short circuits. When ESR'ing capacitor C926 we discovered the values was in excess of 10 ohms, Replacing the capacitor with a new 1000 mfd@35 vdc the ESR 
JVC AV36F703 GJ Dead Model AV36F703 dead but the timer led comes on. Signal diode D535 was found to be leaky  in the x-ray crcuit.  Thanks to FPM in Miami.
JVC HRD840 VCR Dead HRDD840. serial 174J1951. Unit is basically dead. Will not develop and scan signals or light up segments of florescent display. Unit has 30 volt PP pulses at all grids of the florescent display. However there is no clock signal at the EPROM at the instant that power is applied. When the scan signals for the florescent display was scoped, all the grids were being scanned with nearly 30 volts peak to peak scan pulses. But No segment drive pulses. There is communications between the Main microprocessor  and the display Driver. But when checking Pins 5 & 6 of the EPROM we found Data on  5 but only a high on 6. Unit has defective IC702 EPROM
JVC NV55BX4 PU Dead NV55BX4 Will not turn on. Power supply is dead. This television is supported by module replacement only according to JVC It is not recommended to begin any soldering on these boards as they will be replaced by JVC while under warranty. There is a heavey core charge on the modules to insure they get returned. This unit needs The PU-9000A-H1 module Feb-1998. .Update' 10-29-2003 ---- These boards are no longer avalible from JVC. PTS is about the only possible source for this module. Tech may have to send in Module to be rebuilt.
JVC AV27820 FA Dead AV27820 Unit will not turn on. LED in the front flashes, relay clicks, ten goes off. Tech did not leave any details of what the power supply is doing, if any shorts were found in the horizontal output section. Tech needs to go back with schematic to gain more information
JVC AV32720 GKII Dead TV will not turn on. Main degaussing relay RY602 latches but RY921 will not latch.  When checking the IC701(52&53) they both go low when the set it turned on ad high when the set is off. But when checking the switching action of Q925 we find Q925(B) will always stays at 3 volts no mater if the set is on or off. Q925(c) is always low. Unless Q925 turn off it will not turn on Q923 the 13 volt switched supply. Unit has defective Q925.This is a digital transistor. Part # DTC124EKA-X
JVC AV27D303 FE Dead TV will not turn on. Neither RY602 or RY921 will latch.Standby power supply is running but the B+ to the 5 volts lint to the 5 volt regulator IC922 is only 2.3 volts Checking the Inpout of IC922 we discovered it was only 4.5 volts yet IC922 was not running warm to the touch so we went to IC921 we also discovered the B+ was too low on the output and input of this regulator. Looking at the input of IC921 we had 13 volts Peak to Peak ripple when checking it with an oscilloscope. Problem was caused be a defective C926
JVC AV32890 GKIII Gemstar JVC AV32890. Customer complaint is the front timer LED stays on all the time the set is on.  This LED stays on as long as the set is on. The other functions this LED performs is, is to indicate when the set is down loading the TV guide plus data which will make the LED flash. The operation of this LED is normal
JVC AV35790   Gemstar JVC AV35790 TV guide not working. Down loading light always flashing Customer will need to enter an illegal zip code (99999) and allow unit to download. Since this is an illegal zip code the unit will reset as soon as the downloading process begins. After 24 hours the correct Zip code should be entered 
JVC AV32D800   Gemstar Erratic Guide Plus operation.  Symptoms would range from No download information, looses setup information, Guide Plus menu would "black out" except for the pip window.  The most noticeable symptom, and the one I concentrated on, was a "criss-cross" distortion on the Guide Plus menu only.  It was not evident during normal viewing.  I found leaky capacitor C783 on the 5.5 volt Guide plus standby line.  100MFD@16VDC THANKS TO BILL ARNOLD IN Phoenix, Az.
JVC AV27D303 FE Green missing TV has no green. Measuring each cathode of the CRT we found the Red= 166, Blue = 165 and Green = 186 Checking around Q321 we fount the collector to be too high along with the Base at 9.6 and the emitter are 38 volts. These voltages were all wrong. Checking the ohmic value of the emitter resistor of the transistor R325 should be about 330 =ohms, however it was open in the meg ohm range.
JVC AV27CM3   High voltage missing JVC AV27CM3. Unit will not get high voltage. All regulated B+'s from power supply are normal. Collector voltage of horizontal output is 130 vdc. I had tech check the collector of the Horizontal driver Q521. It was "0" volts. This source volts starts out at the soft start supply (Q924) . All pins measure16 VDC. Unit had open trace from emitter of Q924 and the input of the driver transformer.
JVC AV32720 GKII Horizontal Unit has insufficient horizontal sweep. Monitoring the B+ at D921(K) finds the B+ only 105 vdc and unstable. Further checking the voltage at Q1926( C) finds it at 1 volt and Q1926(B) is at "0" vdc. This being a digital NPN transistor it should be "OFF" with this base voltage, removing the transistor restored the normal B+. Note do not shut off in this configuration. The power supply will spike up when RY921  turns off. Replace Q1926 DTC124 corrected the problem.
JVC AV27980 GK3 interference AV27980 Serial #15324665 channels 26-49 have heavy cross talk. VCR hooked up through video inputs shows good pix on same channels. fed cable direct
into TV, no change. changed tuner no change.
Tech needs to get into the tech adjustment area and  set the picture parameters. The parameter necessary is the IC-VCO The original value is normally 64 but the tech may have to massage this value around in order to clear up the cross modulation. Values of under 45 to over 103 are not uncommon.  This one dialed in at value 54.
JVC AV27BP5   Luminance JVC AV27BP5 unit ha a nice normal picture in the tuner or video input mode. But after 5 minutes the picture flashes and goes out but does not loose color or high voltage or OSD. Just luminance Video OK at the input of the comb filter CM201 but lost at the output CM201(5) Suggest tech replace the comb filter part # CE42392-002. Unit had defective comb filter
JVC AV20F703 GJ OSD In the event that board replacement is necessary(due to severe power surge) for the Orion JVC chassis such as models AV20F703, AV24F703 you may run into the following problem with the new chassis: A green letter "N" displays on the screen along with a green square.The JVC remote will not work Using a universal remote, program it for an Orion TV, normally code 091 Turn the tv on Press volume (-) on the TV and the number 1 on the remote at the same time The TV will turn off and will then work with the JVC remote.          Thanks to  Brad Hall from 058:
JVC AV24F703 GJ OSD In the event that board replacement is necessary(due to severe power surge) for the Orion JVC chassis such as models AV20F703, AV24F703 you may run into the following problem with the new chassis: A green letter "N" displays on the screen along with a green square.The JVC remote will not work Using a universal remote, program it for an Orion TV, normally code 091 Turn the tv on Press volume (-) on the TV and the number 1 on the remote at the same time The TV will turn off and will then work with the JVC remote.          Thanks to  Brad Hall from 058:
JVC AV27F703 GJ OSD In the event that board replacement is necessary(due to severe power surge) for the Orion JVC chassis such as models AV20F703, AV24F703 you may run into the following problem with the new chassis: A green letter "N" displays on the screen along with a green square.The JVC remote will not work Using a universal remote, program it for an Orion TV, normally code 091 Turn the tv on Press volume (-) on the TV and the number 1 on the remote at the same time The TV will turn off and will then work with the JVC remote.          Thanks to  Brad Hall from 058:
JVC AV32790   OSD When hitting the menu key the OSD will flash on the screen but disappear very quickly in less than 1 second. If the set was unplugged and plugged in again the OSD would work normally for about 10 minutes but revert back to the same delay as before. Tech needs to look at the 60 Hz reference to the microprocessor. This is the 60 that is routed to the micro through the photo optic isolator in the power supply. The 60 Hz signal gets corrupt and causes the OSD delay counter to increment faster than normal. Tech needs to check the integrity of the 60 Hz square wave.
JVC AV32790   OSD AV32790 When hitting the menu key the OSD will flash on the screen but disappear very quickly in less than 1 second. If the set was unplugged and plugged in again the OSD would work normally for about 10 minutes but revert back to the same delay as before Tech needs to look at the 60 Hz reference to the microprocessor. The is the 60 that is routed to the micro through the photo optic isolator in the power supply. The 60 Hz signal gets corrupt and causes the OSD delay counter to increment faster than normal. Tech needs to check the integrity of the 60 Hz square wave
JVC AV27D200 GR POWER SUPPLY AV27D200. Unit has very low B+ in the stand by mode. Measuring the Secondary B+'s they are only about 50% normal.  Tech needs to see if the power suppply
JVC AV35890 GZ RASTER AV3589 No raster. Unit has no G2 voltage to CRT. Remove C361 cap on G2 source voltage line was removed to see if the G2 voltage returns. It did not. I then asked tech to remove both focus leads from CRT module and reconnect the capacitor C361 and see if the G2 voltage returned.
JVC AV32870   RASTER DARK AV36870 Serial 10230502. Unit has a very dark raster. When measuring G2 the voltage is only 12 volts. When disconnecting the CRT socket the voltage jumps to 340 volts. Unit has a shorted CRT.
JVC AV27980 GK3 RASTER MISSING AV27980 Unit has high voltage but no sound or video. If the G2 is increased the set will have raster. Tech needs to look at the  Data and Clock at the Jungle IC. When checking at IC201(28 &27) the 5 volt peak to peak was OK on  28 the SCL3 was only 1 volt on 27. Isolating the IIC bus's by disconnecting the peripherals discovered the PIP module was loading down the IIC BUS. Internally in the PIP module we found by floating the IC201(23) the load on the Clock line returns to normal. Tech needs to replace the IC201 in the PIP module part number LC74411.
JVC AV27D501 GR2 Raster missing Unit has missing luminance. Sometimes will display an intermittent loss of horizontal or vertical sync. IC201(43) has normal luminance. Freezing IC201 will influence the symptom but not bring back the raster. Tech replaced the IC without effecting the symptom Further checking found the B+ to IC201(16) was only 7.2 volts. Replacing IC971 a AN7809 9 volts 3 legged regulator corrected the problem
JVC AV32D201 GR Raster missing Raster is intermittent and or missing at first when the set is turned. After the set has been running for 10 minutes the raster will stabilize and operate correctly. Tech replaced the Jungle IC and the symptom did not change. Measuring B+ IC201 B+ when the TV is cold the voltage was 8.2 volts and slowly climbed to 8.9 over the 10 minute period. Once the B+ reached the 8.8 level the TV operated correctly. Checking the regulator IC971 AN7805F we found the input voltage to be 12.4 vdc but the output was lower than expected. Replacing IC971 corrected the symptom.
JVC AV27D303 FE Raster missing TV has no raster at all. TV has high voltage, sweep and sound CRT has everything it needs except screen voltage, Measuring the G2 we found about 13 instead of 270 +. The resistance to ground with and without the CRT connected we found the resistance to be 912 ohms. Removing C343 a .001@3KV was leaky. 
JVC AV2781   Raster Weak AV2781 Unit has weak raster and no horizontal or vertical sync. Bad Jungle IC. If the jungle IC were frozen with freeze mist the symptom cleared up.
JVC AV27D302 FD Shut down By definition this really does not qualify as a shutdown but a "fails to run" symptom. When the set is turned on the set will run for about 4 seconds and shut down. It will have High voltage, deflection, and sound. The cause is because the Run "9" volts drops 2 seconds after the set is turned on. The main source for the run 9 volts comes from the 18 VDC standby supply from CN00A(3). This is fed to the 12 volt switch transistor Q952. Q952 is also assisted with a 26 volt run boost from the flyback. The Boost never materialized at turn on. The Boost comes D542(K) which has 26 VDC at "Turn ON" but we did not have 26vdc, ever at D542(K). Unit had defective D542.
JVC AV27D302 FD Shut down By definition this really does not qualify as a shutdown but a "fails to run" symptom. When the set is turned on the set will run for about 4 seconds and shut down. It will have High voltage, deflection, and sound. The cause is because the Run "9" volts drops 2 seconds after the set is turned on. The main source for the run 9 volts comes from the 18 vdc standby supply from CN00A(3). This is fed to the 12 volt switch transistor Q952. Q952 is also assisted with a 26 volt run boost from the flyback. The Boost never materialized at turn on. The Boost comes D542(K) which has 26 dvc at "Turn ON" but we did not have 26vdc, ever at D542(K). Unit had defective D542.
JVC AV32820 FK Shut down Unit will turn on but go into immediate shut down. Tech replaced the Flyback but still had the same problem. When checking the horizontal output Q531(C ) the waveform was badly distorted which was the case before the flyback transformer was replaced. Monitoring the B+ at the vertical output IC421(6) we found only 4 vdc. At turn on. Remove IC421 allowed the set it turn on
JVC AV32720 GKII Shut down Unit shuts down as soon as high voltage comes up. Checking the X-ray protect circuit we found a spike of 4 volts at the D551(A). Checking high voltage finds it to be in excess of 36.5 kilo volts. Monitoring the regulated B+ finds the voltage close to normal at 135vdc. Checking  the pulse width at Q531( C) finds the "OFF" time 10.6 microseconds. Suggest the tech to replace both C1532 (the retrace capacitor) & C1533 (Pin modulator capacitor) Part # . C1532= QFZ0117-12025 & C1533= QFP326GJ-223M.
JVC AV36890   Shut down AV36890 Unit shuts off after 8 to nine hours of constant operation. In order for it to turn back on again the set must be unplugged for 30 minutes then it can be turned back on again. No case history exists on this symptom. An approach to localizing the trouble would be try to heat the power supply, and deflection area with a hair dryer and see if it shuts down. Once the unit has shut down try to isolate the trouble with freeze mist on the end of a "Q" tip and touch each component until the symptom clears up.
JVC AV32720 GKII Shut down TV will run fine until it is turned off but it will not turn back on again unless the power is removed and reapplied again When monitoring any of the secondary B+'s it was discovered that when the TV is turned off the Power supply looses all secondary voltages. When this happens the set looses the stand by voltages too. This chassis has a unique circuit that must act quickly when the TV is turned off. The main supply must be placed in standby mode. The supply was not. When the set turned off all the secondary windings made a momentary spike of over 50%. This spike caused the Main power supply to shutdown because of a over voltage condition occurred. Over voltage occurred because Q926 would never turn on. This transistor when turned on will put the power supply in the stand by mode.
JVC AV27D303 FE Shut down As soon as the TV is turned on the High voltage will climb and then shutdown Checking the presence of vertical sweep we found nothing. Futher checking we found no B+ on IC421(2 & 6). The fix was to replace IC421 (AN5522) and D402 (75 volt zenor diode), D401 (IN4002), and C407 (100mfd@35vdc)
JVC AV32950   SNOWY PICTURE AV32950 Unit has snowy picture on higher CATV channels. The Channels are in the hyper band location. The tuner was replaced without effecting the symptom. Tech needs top confirm the CATV channels on another television of like type. It sounds to me the signal strength is marginal and not consistent across the spectrum
JVC AV27015   Sound Missing Vertical deflection collapse after 30 seconds  vertical IC okay 9volt regulator being pulled down to 3 volts after 30 seconds 9volts goes to vertical oscillator . chip and also the audio processor Found the audio ic 651  #upc1851 bad.
JVC AV36F703 GJ Squeal Customer complains of an intermittent "whistle" or high pitch squeal noise coming from the set. This procedure is not on the JVC website as of now, but is provided by JVC Field Support. This noise problem may be caused by the focus element in the crt.  To verify the problem, disconnect the H-Pulse going to CN00Q on the DAF
(Dynamic Auto Focus) and test the unit for an extended time.  Note: the corner focus will not be as clear with this line disconnected.
Change C2701 on the DAF board to a .27uf/50v mylar capacitor, (JVC part # QFV71HJ-274).  Changing the value of this capacitor lowers the
amplitude of the horizontal pulse going to the DAF circuit.  After replacing this capacitor, focus touch-up is necessary.  This should solve
the squeal problem.
 JVC AV27020   SYSTEM CONTROL AV27020  Tech only getting a blue screen no matter what channel the set is tuned to.. When getting into the "LOCK" menu we find the  Asked tech to enter the service menu mode by Pressing the video status and Display keys on the remote at the same time to reset the television.
JVC AV32890 GKIII SYSTEM CONTROL Unit goes to antenna mode after the set has be configured to CAT mode. This unit needs to be setup in the TV guide mode as well as the main setup mode.
JVC AV32890 GKIII SYSTEM CONTROL AV32890. Unit goes to antenna mode after the set has be configured to CAT mode This unit needs to be setup in the TV guide mode as well as the main setup mode.
JVC AV32950   SYSTEM CONTROL Channel 2 is locked out. Channel 2 cannot be scanned or direct accessed. Tech needs to enter the customer menu and select the channel summary menu. Once this summary is brought up then check to see if the "PAD LOCK" symbol is next to the channel number. If so this channel can be highlighted by using the navigation control and push "0". This will unlock channel 2 if it has been locked out through this menu.
JVC AV36980 GK3 SYSTEM CONTROL AV36980.  Tech claims the television, when turned off will cycle back on 1 or 2 times out of 5 tries.  If chassis is pulled away from CRT it works.  Customer purchased set on 7-4-99. Customer states this set has done this since the beginning. Tech installed a new micro but still did not correct the problem. Yes I do remember talking to Jerry about this. As my notes show the set works but when the customer  tries to turn off the set the set will turn back on again. I mention to Jerry that it sounded like lead dress. Some of the lead dressing from wires that have high EMI flux is too close to a data or analog input to the CPU. I do not know if he checked this or not but is  a logical assumption since when he pulls the chassis from the unit the set will operate fine. However your E-mail states the set shuts off then on again, I'm assuming it does this by itself which will lead me to a completely different conclusion.
JVC AV32820 FK Tuning JVC AV32820 No BT tuning voltage at tuner. D001 measures shorted supposed to be 33 volts.
JVC AV32850   Tuning JVC AV32850. Unit has constant disruption of video & sound on UHF channel 18 and 40. I had tech go into the picture adjustment parameter 20 (VCO ) and move the value from 64 to 43. This cured the UHF channels but did not adversely effect any other channels
JVC AV32890 GKIII TV Guide Plus A32980 Unit will not download TV Guide Plus data Needs to to rest the module by putting 99999 in the zip code. This will force the TV Guide module to reset.
JVC AV35890 GK3 TV Guide Plus AV35890 TV guide will not work. Set experienced a line voltage spike. Tech will need the TV guide plus module. TVGuide plus module not available from vendor.
JVC AV35890 GK3 TV Guide Plus AV35890 Unit will change from CATV to antenna over night. Customer will have the set setup to receive the CATV channels but on the next day the set will not have any  reception above channel 13 The unit has The TV guide Plus feature. It may not be set up correctly. If the unit the unit goes to download the TV guide data It must be able to select the host channel using the PIP tuner. It appears that the customer is using a VCR that is connected to the television. There is no VCR code for this VCR listed in the set up criteria for VCR's. Need to connect this unit without the VCR with CATV going directly to the television for a test. It  operates correctly the VCR is the weak link in the R.F. part
JVC AV2650S   vertical JVC AV2650S. Intermittent vertical sweep Need voltages around IC401for charge pump circuit. Sent fax of schematic area to store for pickup today
JVC AV27850 GV Vertical Unit has no vertical sweep. IC521 has short from IC521(1 & 2)  when the chip is removed. Problem caused by shorted D422 a 75 volt zener diode. Also bad was IC421(LA7832), D421(1N4003) R542(6.8ohm@2watt) & C425(100mfd@35vdc)
JVC AV36950 GV Vertical Unit has retrace lines at the top of the screen. Tech replaced the vertical output IC for a no vertical sweep symptom.  After replacing the chip IC521 the raster was short and retrace lines at the top of the screen. IC over heating. Recommended to replace  IC421(LA7832) again an also the charge pump diode and capacitor. D421(1N4003) & C425(100mfd@35vdc)
JVC AV35770   vertical jitters AV35770 has vertical jitter on channel 43 only. It is unknown what channel this is at the time of this writing.  Problem was confirmed by CATV company Not a fault of television
JVC AV27015   Vertical missing Vertical deflection collapse after 30 seconds  vertical IC okay 9volt regulator being pulled down to 3 volts after 30 seconds 9volts goes to vertical oscillator . chip and also the audio processor Found the audio IC651 651  #upc1851 bad.
JVC AV27820 FA Vertical Sweep missing AV27820 Unit had no vertical sweep and no audio, and replacing the IC541 9V regulator repaired the vertical only. But still no audio. When looking in the customer menu there are no audio adjustments at all.
The composite audio signal was good up to the MTS module, but no left & right audio from it. Somehow the EPROM data had been corrupted or changed. There was nothing unusual in the values of the parameters in the service mode. But if we press "Display" & "Video Status" again, when already in the service mode, it brings up a second menu called "system constants". This menu is a deeper layer of the service menus and lists of 5 System Constants. The last 3 values are called MTS, variable. Out, and Theater. They were set to "NO"  instead of "YES". Tech needs to set these to YES.
JVC AV27820 FA Vertical Sweep missing AV27820 serial 08219533. Unit had no vertical sweep. But after correcting the vertical sweep trouble the set has insufficient vertical sweep and no video or OSD Suggest the tech check the 9 volt regulator ion the chassis. This Is a 3 legged device that has a heatsink on it. It has the numbers 7809 on the device
JVC AV2080S   video missing JVC AV2080S No video or Sound from the tuner or external input. Has OSD. Video present at input of IC851(pin 5) but not after C859 Defective C859 At pin 11 of IC851