Question about JVC AV-48WP30 48" Rear Projection Television

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No responce except thumping noise

Tv went out except thumping noise from speakers. I fixed convergence problem earlier this year with stk chips. can do the repair with the power supply, just need to know what exact part to repair, basic info would realy help. recap, no picture no sound except for thumping noise when powered on, blue light dims alittle with thumping sound.

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Re: no responce except thumping noise


Posted on Dec 25, 2007

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My picture has a red and blue seoaration that looks like an old 3d film

All projection TV sets have two very common problems. One is convergence ( 3D/Warped video or dead set) the other is CRT fluid ( Dull Video). Here are more details and solutions for both.

Common Problem #1) Convergence has gone out

Projection TV sets need to have all three colors - RED - BLUE - GREEN - lined up correctly on the screen in order for the video to look normal. When its out of alignment the video will look 3D, wavy, distorted, etc. In some cases the TV will also not show any video. Most of the time you just need to adjust your convergence in the TV menu. If you cannot adjust it in the menu - then your convergence is broken and needs to be repaired.

This is a very common failure on these projection sets and a fairly simple DIY fix. All projection sets including Samsung, RCA, Sony, Philip Magnavox, Panasonic, Pioneer, Akai, GE, JVC, Toshiba, and others at some point will have the same problem.

Common Symptoms include....

  • Screen looks 3D
  • Colors don't line up
  • One or more colors can't be adjusted when using the convergence menu.
  • Screen is bowed or warped.
  • TV shuts off after powering on. Power light will blink. TV may also make a chirping noise.
Here are some pics of convergence problems.



Common Problem #2) CRT Fluid is Cloudy

Projection TV tubes have a liquid coolant that is used to keep them from overheating. After many years the coolant in the blue and green tubes will become cloudy and cause the screen to look dull, red/orange, etc. You may even see halos around images.

Picture of a set that needs the fluid changed.

TV set after fluid change



You can get the correct parts, step by step photo instruction guides, and support from or click here

Feb 25, 2011 | Sony KP-51WS500 51" Rear Projection...

1 Answer

When my 65 inch Mitsubishi tv is on for about 10 minutes the colors get al blury and almost looks like 3D without the glasses.It is nine years old Model number WS-65819.It doesn't clear up

Your Convergence ICs are likely failing or it is a bad solder joint related to that area. It is very common on rear projections. The solution is to replace the STK chips, check fuses and the resistors next to the STK chips. Replace as necessary and re-align via the service menu. It is about a $300 repair at a tv service center. You will need the service manual if you decide to do this yourself.

Try This:
When you notice the symptons Use this simple test to verify.
Go to the users menu on the tv.
Look for the converge option probably under setup or video setting. Converge is short for convergence to align the red and blue colors to the green color.

If you cannot move the red either horizontal or vertical, then the STK chip has failed for red section.
If you cannot move the blue either horizontal or vertical, then the STK chip has failed for the blue section.

If you can move both in each direction then the problem is something else.

Note if one STK chip fails, you replace both regardless. There may only be one STK chip in this set. If there are two, they will be right next to each other.

Feb 20, 2011 | Mitsubishi WS-55819 55" Rear Projection...

2 Answers

The tv looks like it is in 3d. when i try to adjust the convergiance the plus signs on the left are bent

do not play with this tv replace the stk ic chips and the resistors around the stk chips ,cant miss em about 2 inches big with heat sinks on them.

Sep 11, 2010 | JVC AV-48WP30 48" Rear Projection...

1 Answer

Toshiba 65hdx82 convergence issues

check fuse resistors near STK, and broken PCB around digital convergence board (board in a metal box verticaly mount beside STK.

Apr 23, 2010 | Toshiba 65HDX82 65" Rear Projection...

1 Answer

TV issue

If this is a JVC, you probably have shorted convergence ICs

Aug 11, 2009 | Projection Televisions

1 Answer

Convergence Board (I hope)

check this out I have the same problem check your solder spot make sure the solder points are not touching one another, that could be one of the reason is doing this or just to make sure you can desolder the stk chips clean the holes where the pins go trough the board and power the tv with board and if the tv start fine if could be bad stk chips be very careful when desoldering or soldering good luck about another is not worth it they cost too much around 350-450

Oct 06, 2008 | JVC AV-48WP74 48" Rear Projection...

1 Answer

Philips tv

Sounds like your convergence chips are shorted which would make the set shut down. Its also possible that the flyback has failed but because the first symptom was the 3d look I would start with the convergence repair.

Here are some of the most common symptoms. 

Screen looks 3D
One or more colors can't be adjusted when using the convergence menu. 
Screen is bowed in but stationary.
No audio or video - typicaly occurs after having the distorted color problems listed above. 

You need to replace the convergence chips and convergence resistors. Check the site They have put together a kit for your exact model. The kit includes a photo instruction guide, original Sanyo STK chips, convergence resistors, etc. Everything you need to fix it yourself. 

Hope this helps,

Sep 29, 2008 | Philips 46PP9302 46" Rear Projection...

1 Answer

Screen appears curved on top and bottom

One or more colors can't be adjusted when when using the convergence menu. Screen is bowed in but stationary.


You need to replace the convergence chips and convergence resistors. Check the site They have put together a kit for your exact model. The kit inlcludes a photo instruction guide, original Sanyo STK chips, convergence resistors, etc. Everything you need to fix it yourself. Its an easy fix. 

Jul 22, 2008 | Philips 55PW9363 55" Rear Projection...

1 Answer

JVC AV-48WP30 will not give a picture

Replace the convergence IC`s again using original Sanyo chips (STK 392-110 or STK 392-180). Make sure to use plenty of heat sink compound. Coat the entire back side of the chips. Also look to see if any of the low ohm resistors are burned. A shorted chip will cause the thumping sound and the set will shutdown. I am guessing that you used generic IC`s as a replacement. They are cheap and the leggs fall off when you apply too much heat during soldering. Dont wory about the CRT driver or the deflection board, they are probably fine.

Dec 12, 2007 | JVC AV-48WP30 48" Rear Projection...

2 Answers

JVC AV-48WP30 48 in. Rear Projection

this is the raw research for this that I have found. It seems like the most likely culprit for this is the stk chips on the convergence board (JVC didn't put nearly enough heat sink compound on should be a small layer all the way across they put on a couple dabs) I hear tale you can check this out by disconnecting the convergence board and turning on the set . only go after the convergence board from the front (behind the speaker grill is another panel, the convergence card is right behind there) there is a sneak circuit which will kick in possibly destroying at least the dvi input and mabie more if the set is powered on with the back removed and you didn't put a jumper in the right place or cover over a hole in the back of the dvi module (supposidly to keep people from hacking movies, like there arn't easier ways to do that if you really wanted to). if that doesnt fix it then I have found several other possibilities but I am now a few hundred miles from the tv that I was working on so havent had a chance to try this out:
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
(508)695-7769 FAX
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
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)

Non-functional Digital Input
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

Oct 05, 2007 | JVC AV-48WP30 48" Rear Projection...

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