toshiba 32av502u dead no power

[jkbarto]

had power outgage from utilty company,when power came back up
tv was dead no power, no light, checked power board ,blown fuse ,replaced fuse , blew again, ordered new power board and replaced,still no power on tv
checked fuse good,but only has 48-50 volt at fuse ,is this voltage ok
is this replacement board bad or is there another board that might be bad?

[selldoor]

Re: toshiba 32av502u dead no power

If you are talking about the mains fuse then no , it should be 120VAC or close. Check the lead and the fuse holder - is this on the New board?,
tray another lead?
Welcome to the forum-
We can help a lot more if you please post good clear pictures of the whole chassis, and then pictures of each board, front and back and close up of connectors, (max resolution 2000x2000 and 2MB) using the manage attachments button, which is found by clicking "go advanced" under quick reply.

Please do not post inline and offsite as they slow down the loading of pages.

Examples of what is needed
https://www.badcaps.net/forum/attach...1&d=1290283049

https://www.badcaps.net/forum/attach...7&d=1280167246

It will be useful if you can say a bit about yourself - skills tools etc.

[retiredcaps]

Re: toshiba 32av502u dead no power

1) How are you measuring the fuse?

2) AC or DC?

3) Where are you putting the black and red probes when measuring the fuse?

[jkbarto]

Re: toshiba 32av502u dead no power

red lead is at fuse and black lead on ground screw i get 48 volt ac
if i measure from fuse on red lead and white on ac cord i get 120 volt

[budm]

Re: toshiba 32av502u dead no power

Unplug the TV from the outlet, set the Meter to the lowest Ohm scale, I.E. 20 or 200. Red probe on one end of the fuse, black probe on the other end of the fuse, report back what you read.

[jkbarto]

Re: toshiba 32av502u dead no power

i get 1.3

[budm]

Re: toshiba 32av502u dead no power

I expect it to be less than 1 Ohm but that may be due to probe lead resistance and weak batteries in the meter.
Next, set the meter to DC high range above 250VDC, put the meter probes on that large brown/black cap with two exposed legs in the pictures, be cureful since you are working on the line voltage, polarity dose not matter since the digital meter does not care, I expect to see around 170VDC on that cap with the TV plugged in. BE CAREFUL!

[retiredcaps]

Re: toshiba 32av502u dead no power

red lead is at fuse and black lead on ground screw i get 48 volt ac
if i measure from fuse on red lead and white on ac cord i get 120 volt

One retiredcaps' bonus point for a picture your Beckman Tech 310 multimeter.

The reason you are getting 48V AC is because you are using chassis ground.

Your reading of 1.3 ohms suggests the fuse is likely good. I say "likely" because if your multimeter reads around 1.0 ohms with the leads touching, then the fuse is actually 0.3 ohms.

edit: Budm beat me again by 1 minute!

[jkbarto]

Re: toshiba 32av502u dead no power

here are picture of chassis and boards

[retiredcaps]

Re: toshiba 32av502u dead no power

next, set the meter to dc high range above 250vdc, put the meter probes on that large brown/black cap with two exposed legs in the pictures,

c102.

[jkbarto]

Re: toshiba 32av502u dead no power

cap reads 165vdc

[selldoor]

Re: toshiba 32av502u dead no power

Ok looks like it might be ok just as a last check. Meter on 200 VAC measure from the white lead to each end of the fuse- you did one end please do the other end.

Next test - Board powered on -CARE HIGH VOLTAGE meter on 600VDC put red probe on to + leg of the BIG Cap and Black Probe onto negative leg of the BIG Cap



WOW you lot are keen - im off to bed.

[budm]

Re: toshiba 32av502u dead no power

OK, if you look at the left side of the board, you will see P802, you can see that it has label on the board telling you what you should have at the pins, in this case, with the TV is not turn on but plugged in, you should have standby 5Vdc voltage at pin 10, 11, 12 of P802 as shown on the board, black probe on the chassis, red probe to the pin we are testing.

[jkbarto]

Re: toshiba 32av502u dead no power

white power lead and other lead to fuse 120volt
black ac power lead and other lead to fuse 0 volt

cap at c102 is 165vdc

[budm]

Re: toshiba 32av502u dead no power

See post 13.

[jkbarto]

Re: toshiba 32av502u dead no power

pins at 10 11 12 no voltage ,no voltage on any pins ,p802 goes to processor/tuner card

[budm]

Re: toshiba 32av502u dead no power

That explain why you do not have any indicator lights, and dead set. We need to troubleshoot the 5V standby power supply section next.
It is generated from that small transformer T001 and that 8-PIN IC, cannot read the number due to the flash glare. Please get the P/N as printed on that IC so we can look up the spec and see how it works.

[jkbarto]

Re: toshiba 32av502u dead no power

pk101v0730i

[jkbarto]

Re: toshiba 32av502u dead no power

top view

[budm]

Re: toshiba 32av502u dead no power

That is the number of the board, I need the P/N of the 8-pin IC on that board