Question about JVC AV-48WP74 48" Rear Projection HDTV-Ready Television

2 Answers

Where is the deflection board

I have the thumping sound and a flashing blue power light, after I replaced the stk-392-110 components, can you tell me what happened?

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  • Anonymous Nov 28, 2007

    I have a similar model tv that I was working on that began thumping and replaced the stk 392-110's to no avail. in my case I know for sure that the soldering is fine (iv'e been doing it for years and checked all connections for shorts and opens before I put the board back) Might be a while before I can get back to it though since the TV is in Pittsburgh and I was just visiting for thanksgiving.

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Some things I have found that you could try

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
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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

Posted on Dec 06, 2007

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Was there a change in symptom from original?? Then recheck
your soldering with meter....short circuit???? Let me know...T.

Posted on Nov 26, 2007

  • Vista Electronics Nov 26, 2007

    Ps. Check all fuse devices after you find short.................T.

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I have a Pt-56hx41pf Panasonic and when I turn it on it trips off with a red light next to the led power button flashing. When I turn it on again it wont come on. If I unplug it the tv would come on to...


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Won't power up and power button light flashes


when you replaced the convergence amps did you check and replace the resistors? it seems like they always take out two or more resistors. the problem is on the convergence board, i have the same tv that did the same thing. if the speakers are still thumping, you may have got a dud amp. i recommend using the factory stk392-110 amps. make sure all of your solder connections are good and none of them are touching. also, when you get the set back on you will need to manually adjust the convergence from the menu. you will need the factory remote. if you find bad resistors, the values are on them, but if you need the values and wattage, then use this page:

http://home.comcast.net/~dande76530/ConvergenceOutSchematiics.pdf

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JVC AV-48WP30 will not give a picture


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No responce except thumping noise


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What was happening before can put you close to what when out. If you had color problems or sound, or even picture going small. these are symptoms that causes the set to go out. If color look in the convergence area and look for blown fuses and bad resistors. If just went out the look at horizontal output transistor.

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