Toshiba 32BV702B- DEAD

[WallArt-Online]

Hi,

I was asked if I could have a look at the above tv, there is no display, sound, leds, or anything showing any sign of life before I opened it.

I took the unit apart and couldn't see any obvious damage. Not having knowledge to check voltages or anything I suggested that it was more than likely the power supply board that was dead seen as though there was no standby light lit. After discussing this we purchased a replacement board from ebay and fitted it, I then tried the unit again, -same result no power.

After unplugging the tv I noticed the plug had a 13 amp fuse in but the plug states 5amp, I replaced the fuse and tried the unit again but still nothing.

Could the 13amp fuse of blown something? Would any of the other 2 boards cause this problem? or do you think the replacement board could be shot?

Any help appreciated

Ps the power board is a 17PW25-4 V1

Thanks

[tom66]

Re: Toshiba 32BV702B- DEAD

Check the fuse on your power board (not just the one in the plug) and check for burn marks/discolaration around the transistor mounted on the heatsink.

The plug should use a 3A or 5A fuse, the fuse is ONLY to protect the plug and wiring. The equipment should posses its own internal fuse to protect itself.

99% of the time a dead set on these Vestel PSUs it's a blown primary transistor due to shorted output diodes. TV is built by Vestel which is an OEM, the same TV is sold under the likes of Technika, Alba, Bush, etc. utter rubbish and a shame Toshiba is rebadging such.

[WallArt-Online]

Re: Toshiba 32BV702B- DEAD

Are you refering to the part i have circled in red?

Also the part in orange was not on the original board I swapped but the model of both board is exactly the same

[zomi]

Re: Toshiba 32BV702B- DEAD

Did you swap the capacitor too ?
the one infront of the part circled in orange ?

[WallArt-Online]

Re: Toshiba 32BV702B- DEAD

No I never swapped any components, that board pictured is the replacement I purchased on ebay, was stated that it was tested and working.

[zomi]

Re: Toshiba 32BV702B- DEAD

I have cricled in green
I think this will not also be present in your purchased psu...

[WallArt-Online]

Re: Toshiba 32BV702B- DEAD

Is there a way to test it with a multimeter?

[WallArt-Online]

Re: Toshiba 32BV702B- DEAD

Just realized what you have said, Why would it be missing on one board?

[tom66]

Re: Toshiba 32BV702B- DEAD

Wait... are you saying the power board you bought from eBay had the device on the heatsink missing?

[WallArt-Online]

Re: Toshiba 32BV702B- DEAD

Ok even i'm getting confused here.

The board pictured is the one from eBay, It has the exact same markings stamped (model number and revision) but has the extra black plug bit on (circled in orange).

Zomi has said he believes the original board (back in the unit) will have the green cap missing.

[nomoresonys]

Re: Toshiba 32BV702B- DEAD

might have gotten a mismatch, sometimes theres 3 or 4 different boards for same model but they dont all necessarily match with the other boards.

[tom66]

Re: Toshiba 32BV702B- DEAD

Oh. I think I understand now.

That black plug is for a mains switch. Since your set does not have such a switch you will have to bypass it. The best way is to solder a jumper wire across the bottom terminals.

[WallArt-Online]

Re: Toshiba 32BV702B- DEAD

your joking?! All I probably have to do is short that out?

[tom66]

Re: Toshiba 32BV702B- DEAD

Yes. I've had to do it before on other Vestel power boards when using incompatible ones.
Note, if you get a blinking LED and set not powering on after doing this, there is one more thing you need to do (but we'll deal with that later.)

[WallArt-Online]

Re: Toshiba 32BV702B- DEAD

It's now blinking red and green

[tom66]

Re: Toshiba 32BV702B- DEAD

Ok pull the board out and get a picture underneath the area of the connector that goes off to the main board.
Needs to be clear and in focus... you have to remove a small component to convert the board to the compatible version.

[WallArt-Online]

Re: Toshiba 32BV702B- DEAD

Hope this is clear

[WallArt-Online]

Re: Toshiba 32BV702B- DEAD

comparing the boards is it S814 that needs removing?

[tom66]

Re: Toshiba 32BV702B- DEAD

Ok, S814, see next to the connector? It's the component with "0" marked on it. Simply apply solder to both ends and slide it off. It's a zero ohm link - basically, a piece of wire in a box.

edit: you beat me to it... good eye

[nomoresonys]

Re: Toshiba 32BV702B- DEAD

this is COOL how you guys made it work. you didnt have to buy a new board.