TOSHIBA 46RV555DB No picture but sound back light is on

[Andyd1970]

Hi All,

Help please! I have a 46 inch TOSHIBA RV555DB that has sound but no picture! The back light is on as you can see it through the holes in the metal panel behind the screen. The PSU does make a whine when it is first switched on. I was wondering if it was T-Con? I am prety good with a meter so wondered if I could prove it by checking some voltages?

Thank you in advance

Andy

[tom66]

Re: TOSHIBA 46RV555DB No picture but sound back light is on

Could well be the T-con.

Pictures of the insides of the TV would help us help you. Especially a clear picture of the T-con.

[Andyd1970]

Re: TOSHIBA 46RV555DB No picture but sound back light is on

Hi Tom66,

Thank you for the reply, great to know people are out there with your knowledge.

See attached pics of the back of the TV to give over view and close ups of the T-Con.

Thank you for your help.

Andy

[tom66]

Re: TOSHIBA 46RV555DB No picture but sound back light is on

OK, with your meter, can you test the voltage on both ends of "F1" on the t-con? It's that white/gold object near the left main data connector.

[Andyd1970]

Re: TOSHIBA 46RV555DB No picture but sound back light is on

Hi Tom,

Just checked and I read 12.1volts each side, it did dip to 11.3v for a moment and then back upto 12.1v. I did notice a constant ticking from the PSU.

Andy

[tom66]

Re: TOSHIBA 46RV555DB No picture but sound back light is on

I think you'll need to remove that shield from the 100Hz processing board and get a picture of that. Perhaps something on that is bad. Is the ticking a relay clicking sound or quite faint?

[Andyd1970]

Re: TOSHIBA 46RV555DB No picture but sound back light is on

Hi,

I have removed the shielding and cannot see any obvious damage or bad components, I used an eye glass to look closely. See attached pic. The ticking sounds like a relay ticking in the bottom left hand side of the PSU.

Andy

[tom66]

Re: TOSHIBA 46RV555DB No picture but sound back light is on

Check the voltage across this cap.

[Andyd1970]

Re: TOSHIBA 46RV555DB No picture but sound back light is on

12.2 Volts on the top of each of those caps, and 11mv on the bottom of each of them.

Andy

[tom66]

Re: TOSHIBA 46RV555DB No picture but sound back light is on

OK, let's try a different angle. On the PSU, can you locate exactly where the clicking is coming from?

[Andyd1970]

Re: TOSHIBA 46RV555DB No picture but sound back light is on

I am pretty sure it is coming from SR80, which is in the bottom left hand corner of the PSU it is the the second from bottom relay, in the attached picture.

So the checks we have done has that proved the T-Con and the other board are ok?

Andy

[tom66]

Re: TOSHIBA 46RV555DB No picture but sound back light is on

It proves they have power but nothing further. Hmm, the TV stays on through the ticking sound?

[Andyd1970]

Re: TOSHIBA 46RV555DB No picture but sound back light is on

Yes the TV is still on and the sound is clear and not distorted.

[tom66]

Re: TOSHIBA 46RV555DB No picture but sound back light is on

How frequent is the ticking? About once a second, faster, slower?

[Andyd1970]

Re: TOSHIBA 46RV555DB No picture but sound back light is on

It is quicker that once a second. The board to the left of the PSU just shows the bottom of it in the last picture when first switch on the transformer on it squeals and then settles after about 5 seconds.

[tom66]

Re: TOSHIBA 46RV555DB No picture but sound back light is on

Use a toilet roll tube to locate the exact source of the sound.

[Andyd1970]

Re: TOSHIBA 46RV555DB No picture but sound back light is on

100% SR80 is ticking

[tom66]

Re: TOSHIBA 46RV555DB No picture but sound back light is on

It is whining or ticking?

[Andyd1970]

Re: TOSHIBA 46RV555DB No picture but sound back light is on

SR80 is just ticking I guess about 2 times per second.

[tom66]

Re: TOSHIBA 46RV555DB No picture but sound back light is on

So where is the whining coming from?