TV PROBLEM I have a JVC screen. When you power it on several clicks are heard and some sparking is seen on the pcb attached to the tube. Then it glows white with lines. No picture no sound and no response form both the remote controller as well as the buttons on the set. What can be the cause and how can I rectify the problem?

hi..It sounds like your tube Shadow Mask may have got
magnetised and need to be degaussed.turn off your TV
at the mains and unplug it for at least two three hours,
after that time power up your TV it should degauss the
tube at power up.
try this out..
thank u..
kindly rate my response..

You most definately have bad capacitors in the power supply. try and get it repaired as soon as possible, not an expensive repair that iv'e seen.

Tri to remove the concergence pcb assy and start the Tv.If the TV is working just replace the convergance IC.

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

havent had time to check these things out but here is some raw research I have done

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)695-7302
(508)695-7769 FAX
geminitv@xxxxxxxxxxx
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

have you considered a bad fly back? good luck

You didn't mention if you saw fine white diagonal lines running through the screen from top to bottom. If so, you likely have a shorted Picture Tube which is not usually fixable. If there are no lines seen running through the screen, then it is possible the High voltage transformer which also has a screen voltage and focus control built in that could be bad. I would expect the cost of that part to be about $100, so the repair cost total could approach that of a new set I would guess.

you have to get into the tv to do the adjustment. take the cover off and then look for the CRT tube and follow the yoke cables that will lead you to the printed circuit. you should see some small tiny knobs there. something like vertical phase or horizantl Phase..you need the verital to adjust the vertical size of the pic..good luck

When a direct view set fails after (minor) impact it is usually due to PCB fractures - and then it is usually fractured around the flyback transformer (because of the weight of the component), but may be cracked elsewhere. Patch jobs around the flyback are typically easy. If the board is badly fractured use some stiff wire in the patching to give the PCB some rigidy and prevent further aggrevation of the fractures. I would assume you did not bust the picture tube as you would have heard that one :) If this is one of those vcr/dvd combo jobs then you may have to look elsewhere for the fractures.

Hi What you are discribing is a condition call power supply overcurrent shutdown the TV is going into a protection mode to prevent further circuit damage you really to call in a tech with JVC projection TV repair skills to fix this problem for you good luck windman