Toshiba 32av502rz

[Vizor]

Bought this a few days ago.

1. Backlight is blinking off and on really really fast.
2. Red light on the Input board is blinking off and on red and speaker on the right side facing down is making a popping noise.

5V is all over the place.
12V is all over the place.
24V is at 23.5V

165V on Both Big Caps.

i have a power supply from a TOSHIBA 32AV502R but its missing capacitors.
photo to that power supply is http://assets.shopjimmy.com/media/ca...k101v1070i.jpg

if someone could help me find out what caps it needs.

[tom66]

Re: Toshiba 32av502rz

Classic symptoms of a bad startup cap - one of the small ones on the side marked "primary". Likely the two small ones next to each other. Try replacing them as they are low cost (20 cents each...)

[Vizor]

Re: Toshiba 32av502rz

Replaced them with PEC"s and still nothing.

[tom66]

Re: Toshiba 32av502rz

Replaced them with PEC"s and still nothing.

Okay; I'm thinking that it's a shorted output diode, or an excessive load. How does the TV behave without the inverters connected? Also, check TVS801 for shorts.

[Vizor]

Re: Toshiba 32av502rz

Stable 483 on TVS801 still behaves the same way regardless if the inventer is hooked up.

[tom66]

Re: Toshiba 32av502rz

Stable 483 on TVS801 still behaves the same way regardless if the inventer is hooked up.

483 both ways? Or only one way?

The layout of the PSU is conventional. The 5V standby is produced by the small transformer. The 12V and 24V are produced by the bigger one. The odd thing is, you say the 5V and 12V are unstable, but the 24V is not. That is very unusual. Can you double check the 5V is genuinely unstable? (How unstable... 0.1V or 1V or 5V ripple?)

[Vizor]

Re: Toshiba 32av502rz

483 just one way. 1 otherway. i guess i was wrong no 24v or 12v and no 5v its all going between 1.245 and some other numbers but its all over the place.

[tom66]

Re: Toshiba 32av502rz

So all the outputs are unstable?

[Vizor]

Re: Toshiba 32av502rz

yea.

[tom66]

Re: Toshiba 32av502rz

yea.

Okay from what I understand of these Toshiba PSUs the two big caps are wired in series and form a voltage doubler. I'm not sure why they do this. If one cap goes bad, it will cause the doubler output to drop out.

Check the voltage across from one negative terminal of the cap to a positive terminal. I *think* you should see about 330V.

[Vizor]

Re: Toshiba 32av502rz

uploading a very small video with the noise and showing what the backlight does. but to me it seems like its surging http://www.youtube.com/watch?v=pxCjYnrEwAM

[Vizor]

Re: Toshiba 32av502rz

Big caps go between 328 and 330v

[tom66]

Re: Toshiba 32av502rz

Okay, so they do wired them in series as a voltage doubler. One more mystery solved, although why they do that escapes me. 328-330V seems okay for a doubler output.

How is the PSON pin on the power connector? Does it stay steady or vary?

Are you ever able to get the TV to go into a standby mode where it doesn't try to start up? If so, what does the standby supply measure at?

Also, I know some Toshiba TVs do a self-test when plugged in. So it could be that it is doing this test and failing, which would mean it is failing at the first hurdle and so won't go into standby.

[Vizor]

Re: Toshiba 32av502rz

POW is all over the place but ACD is going between 65 and 75v. don't see anything labeled PSON

and the tv doesn't do nothing but sit there and make that noise and flash the backlight

all the connections are going from 1.245 and onward.

[tom66]

Re: Toshiba 32av502rz

POW is all over the place but ACD is going between 65 and 75v. don't see anything labeled PSON

and the tv doesn't do nothing but sit there and make that noise and flash the backlight

all the connections are going from 1.245 and onward.

Where is your black probe connected?

[Vizor]

Re: Toshiba 32av502rz

where the screws go.

[tom66]

Re: Toshiba 32av502rz

where the screws go.

65V on the AC detect is very unusual, are you using AC or DC?

[Vizor]

Re: Toshiba 32av502rz

lol guess i am not that bright today.

its reading 11v.

[tom66]

Re: Toshiba 32av502rz

That seems okay. Is your other Toshiba board the same as this one? I'm suspecting the device SCR1; it's an overvoltage protection "crowbar"... If something is wrong with it, it may be firing too early. Does your other board have SCR1?

I'm going to bed now... I'll post in the morning.

[Vizor]

Re: Toshiba 32av502rz

other board doesn't have SCR1 its made by a different company.