Top 10 JVC AV-48WP74 48" Rear Projection HDTV-Ready Television Questions & Answers

try replacing the stk's on the deflection board (making sure that all of the resistors on the board are OK and that there are no solder cracks I found one of the jumpers had a bad solder joint on the one I worked on) but if that doesn't fix I have some raw research that might give you somewhere to start :
No. The CRT driver ICs are prone to shorting and cause this symptom (I just had one with those very symptoms and the green CRT driver IC was shorted). Disconnecting the CRT board does not clear the short on the board. Often then is a small burn mark on the CRT board under the affected IC (but not always). The IC should be a TDA6111Q. Be sure to note the proper position
of the IC as it should face with the letters TOWARD the heat sink!!!!

Larry, Check the CRT driver ICs on each of the CRT boards.
Bob Waterman, CET® #RI-28
Master Technician License #9109
Service Manager / Parts Manager
Gemini Computer, TV, & Security Alarms
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Hi Guys, I don`t see many JVC`s and don`t have the print for this AV48WP30, went out this morning and as customer claimed on phone when you plug set in and turn on it makes a loud thump thump in both speakers 20-30 times then relay clicks, the thump stops, and blue idiot light on front goes dim/bright, dim/bright, have to unplug set to start this same scenario over again. Never develops HV or audio, Will order the service manual today, but would like to know if anyone has seen this before (should say "heard" this before)
I would disconnect each crt board and hv lead one at a time and try. Have seen several bad tubes on that model. The only other problem I have seen on that set is bad convergence amps, however that doesn't cause shutdown.
Perry Bower
Electric Medic
From Tech Repair CD:
JVC\AV48WP74\just went click*click*click when turned on Video drive IC (IC1101) on the red CRT module
shorted. It looked like bad solder on the B+ was the cause

Frequently Used Top Five Repair Parts by symptom code
MODEL NUMBER : AV48WP30 - TV
SYMPTOM CODE : DEAD
TOP FIVE PARTS :
2SC5552-RL
2SC5904-RL
QQH0113-002
STR-F6629B/F7
STK392-110
Above from JVC Web site, also I have seen shorted video drive IC's on the crt boards short and cause this symptom. Try unplugging the 200 volt source to the crt boards and see it the set powers up and stays on. There is a B+ relay which supplies 130 Volts to the horizontal output circuit. Is this relay energizing? I takes about five seconds after the power is turned on for it to energize. If a short is detected on the 130 volt line the blue power lamp on the front will do what you describe and the relay will pulse on and off. (David)

Symptom:
Non-functional Digital Input
Solution:
1. Power off the unit
2. Disconnect the digital input if it is connected
3. Remove the rear cover
4. On the digital input module, using a shorting pin (PC type) or a
jumper, short Pin 1 and Pin 2 of the
SB connector
5. Power on the unit
6. Unplug the unit and remove the shorting pin or the jumper
7. Re-attach the unit’s rear cover
8. Power on the unit, and input the digital source

I had a problem with my TV colors not lining up. One day I turned it on and the green was out of wack. I checked this message board and replaced the STK chips, bad soldering and all led to me just giving up on that and buying a whole new Convergence Board ($185). I just plugged this in and though now my Green lines up okay, my red is out of whack. Is there something I am doing wrong? Can anyone help me? Did i miss a step? Frustrated......Bruce

Remote control original is part # RM-C1200G-1H ...best to
have JVC original......$25.00......................T.

if you lose your video or weaken the video driver you just might be looking at straight color that looks funny like you described... but looking at this picture ... I see the flash from the camera and and lots of video (the black and white) but it does look dark over-all... which I would first try to reset my screen control that is located on the bottom of the flyblack.
the convergence looks fine.

you can get the convergence repair kit to fix your model JVc at the following link look under the convergence repair kit category, they provide free step by step instructions with pictures so you can easially do the repair yourself. heres the link.
http://servicemanuals.vstore.ca/

Hi sbatsch,

Not to worry - this problem is very common with projection TVs and is easily fixed:

The reason for the green shadows (and the resulting wrong colors) is that the three color tubes (red, green, and blue - the three colors of light that combine to form all the other colors) are not lined up exactly - this lining up is known as "convergence." You can fix convergence automatically or, if it doesn't work to your satisfaction, manually. Here's how:

Automatically:
1) Press MENU.
2) Go down to CONVERGENCE (using the up and down arrows)
3) Select it (usually with the left or right arrow)
4) Go down to AUTO and select it - the process should take about a minute.

If this doesn't work, then try manually:
1) MENU
2) CONVERGENCE (as above)
3) Select MANUAL
4) Using the number keys, SELECT, and the arrow keys, adjust the alignment of the different color crosses - the goal is to make them appear white (meaning that the red, blue, and green are exactly aligned on top of one another).

Here's a link to the JVC user manual that will explain the manual convergence adjustment in more detail.

http://resources.jvc.com/Resources/00/00/96/52105ien.pdf

I hope this helps - please let me know if I can be of any further assistance.

Hello pzemenides,

I posted this in an eariler solution and there are numerous referencesto this type of problem on fixya.com, however it fits in this case, sohere it is:

This denotes a convergence problem. Believe it ornot it would be cheaper for you to replace the two convergenceamplifiers and the biasing resistors. You would not actually bereplacing the convergence board since these devices are usually locatedon the deflection board in most cases. However in answer to yourquestion, the boards are easily removed, depending on your level ofpatience (lots of cables to move around), I would also advise you toeither mark down all of the connection you will remove, or take picturesof the board and its connectors. If you choose to just replace theAmplifiers and the biasing resistors there is a lot of information onthis site on how to do so: This will get you started:

1) Unplug the TV and then get a schematic of the TV I use http://www.servicemanuals.net or http://www.manualsparadise.com
2) On the schematic locate the STK392-xxx series IC packs (or whatever Convergence ICs your set is using) (usually attached to a large heat sink)
3) determine if the STK392s are 110, 120 or 150.
4) if the STK392-xxx's are 110s replace with 110s (forget that upgrade stuff it is a hit or miss game that I don't believe you want to get into), if they are 120s replace with 120s and so on.
5)Nowto replace the STKs: remove the module from the TV and unsolder theoldSTKs along with the bias resistors, and replace them with the newones(be sure to apply heat sink paste to the STKs when attaching them to the heatsink)
6) make sure there are no short circuits form your soldering job.
7) Reinstall the module and then turn on the TV.
8) do manual adjustment and the auto-convergence test and then things should be back to normal.


I hope this helps

Shuttle83

http://www.electron-age-technologies-llc.com

Press SLEEP TIMER and, while the indication of (SLEEP TIMER 0 MIN) is being displayed.
press DISPLAY and VIDEO STATUS on the RC simultaneously. Exit: EXIT.

The convergence ICs and feed resistors need to be replaced. You can get the repair kit for your specific model at the following link. The convergence repair kit contains the replacement parts and the step by step repair proceedure on CD. Very easy repair. Just look under the JVC repair kit category
http://www.tvrepairworld.com/

Okay so the green color that you see on the screen is because the coolant inside of the green picture tube is gone bad (it suppose to be cristal clear but now it is brownish and that makes the green color run all over the screen.) That just happens over time and I'm guessing the picture tubes have never been serviced. Now you got two choices
1- The easiest and fastest way would be to take it to a local repair shop and have them service the coolants of your picture tubes. I'm guessing it would run you about $165 or so to get them done (the three of them red,green and blue)
2-On the other hand you can do it yourself. It is not hard at all but it does require a lot of attention.

After the picture tubes have been serviced you'll notice the big difference.
You'll actually have a much brighter and sharper picture just like when it was new.

Let me know if you decide you want to do it yourself so i can post the instructions for you.