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Equipment Repairs => CRT TV forum => Topic started by: petermark on February 20, 2011,11:54:58

Title: toshiba 43 inch rear projection tv
Post by: petermark on February 20, 2011,11:54:58

i hve a 43vj33q toshiba thats stuck in standby . it makes no attempt to start up at all with either remote or front buttons  . i have replaced the three convergence ics which made no difference . i can get the power supply to operate by shorting pin 3 + 4 on the microprocessor and all the voltages seem ok according to the service manual but there is no pic or sound . wondering now do i have a microprocessor problem or maybe a corrupted eeprom . anybody have any further ideas

regards

peter

Title: Re: toshiba 43 inch rear projection tv
Post by: Turnip on February 20, 2011,12:02:59

Hi P/M,

There's talk of PS fuses in back threads - nothing else - Chris.

Title: Re: toshiba 43 inch rear projection tv
Post by: JAYROD on February 20, 2011,19:38:09

Peter, on most toshiba rear projector tv`s the most common cause of this fault is a faulty text module.The tv will work if you remove it. Also the 100 hz modules are prone to faliure. 

  Phil.

Title: Re: toshiba 43 inch rear projection tv
Post by: janongpao on February 21, 2011,05:24:12

HI
This should be the protection of the machine moves, the most likely site is the convergence circuit failure

Title: Re: toshiba 43 inch rear projection tv
Post by: petermark on February 21, 2011,07:10:35

i have looked for the text module but cant seem to find it where is it located on this set . i have also replaced the convergence chips but they made no difference

regards

peter

Title: Re: toshiba 43 inch rear projection tv
Post by: JAYROD on February 21, 2011,08:54:53

Sorry peter i have had a look at the circuit diagram for this model and toshiba have combined the micro and txt in to one ic on this model. I have attached the service manual for you.

  Phil

Title: Re: toshiba 43 inch rear projection tv
Post by: Keith on February 22, 2011,05:38:11

Hi,

If it was a protection problem the set would try to start and then go to stand by. Make sure the remote control is working OK, check the frequency is correct on the oscillator xtal. The sets front buttons could be locked so it will have to be turned on from the remote.
Usual problems are psu fuses, wire ended usually white in colour, check all of them.
The text boards were a big problem with these, its the small board on the small signal / micro panel. But the usual problem is no picture or intermittent picture, the board can be removed without modification.
We never had convergence chips put the set into protection, just bad convergence.
The only micro problems were due to high humidity in sets in beach bars or beach restaurants causing corrosion of the boards.
Also check the tubes haven't leaked coolant fluid, as that will also destroy the boards it gets on.

You need to consider if its worth pursuing, as the tubes could be well passed their best by now.

Good luck

Keith

Just noticed this is the one without the text board! Thanks JAYROD. Didn't see many of these, but still check those wire ended fuses, and remote control oscillator.

I would also suggest putting the original convergence chips back in, as there were lots of cheap and underrated ones about that caused lots of problems. Gave me head aches, but the Greek Raki made things right!

Title: Re: toshiba 43 inch rear projection tv
Post by: petermark on February 24, 2011,17:00:49

many thanks for these replies . will check everything mentioned

regards

peter