Toshiba 24d1434db / Vestal 17IPS61-3 help

[dooosuk]

Hi,

I'm new to this so please bear with me. I've been reading plenty of threads and so I'm hoping I've tracked down my issue.

My toshiba 24d1434db has no power, not even the standby led.

The capacitors all look OK and there doesn't appear to be an obvious blown component from looking at the board.

I've found threads for the Vestal boards which appear to indicate faulty diodes may be the issue.

I've tested with a multimeter and get the following readings:

D8 - no diode fitted
D9 (UF5402) - 0500 and 1000 when poles reversed
D10 (SB5B0) - 0030 and 0050 when poles reversed
D11 - no diode fitted
D12 (SB5B0) - 0030 and 0050 when poles reversed
D25 (SB5B0) - 0030 and 0050 when poles reversed

So I understand it's likely to be only one of the SB5B0 diodes but I'm best replacing them all. Can I fit a better diode? Any suggestions?

Should I replace the UF5402 diode as well or is that reading all ok and best left as is?

Can I fit extra diodes in D11 and D8 without any issues? (On one thread someone appeared to do this). Would this reduce the chance of a future re-occurrence as well as using thermal epoxy?

Thanks, your help is appreciated.

[vinceroger69]

Re: Toshiba 24d1434db / Vestal 17IPS61-3 help

with diodes if im not sure i always unsolder and lift one side off the board and retest that way sometimes you can see if diodes are leaky too.

[ReeceyBurger123]

Re: Toshiba 24d1434db / Vestal 17IPS61-3 help

Checked if you have a voltage on the other side of the diodes ?

[dooosuk]

Re: Toshiba 24d1434db / Vestal 17IPS61-3 help

Checked if you have a voltage on the other side of the diodes ?

I thought I'd read the voltages on both sides and listed them above. Will re-check with my multi-meter later but sounds like I probably need to unsolder one side first.

[dooosuk]

Re: Toshiba 24d1434db / Vestal 17IPS61-3 help

Right, so I've de-soldered the diodes and taken the readings again

D8 - no diode fitted
D9 (UF5402) - 0500 and OL when poles reversed
D10 (SB5B0) - dodgy
D11 - no diode fitted
D12 (SB5B0) - 0300 and OL when poles reversed
D25 (SB5B0) - 0300 and OL when poles reversed

So, my original questions still stand

I'll replace all the SB5B0 diodes but is there a better diode I can fit? Any suggestions?

Can I fit extra diodes in D11 and D8 without any issues? (On one thread someone appeared to do this). Would this reduce the chance of a future re-occurrence as well as using thermal epoxy?

Thanks, your help is appreciated.

[vinceroger69]

Re: Toshiba 24d1434db / Vestal 17IPS61-3 help

tom66 in another thread recomends these
http://www.ebay.co.uk/itm/UF5408-Rec...item25789d54dd

https://www.badcaps.net/forum/showthread.php?t=41922

But if it was my set i would replace like for like with the diodes but i would change all of them in one go

[tom66]

Re: Toshiba 24d1434db / Vestal 17IPS61-3 help

Those, or MUR460 / HER308G.
Needs to be a fast diode, so 1N5408 is no good. UF5408 is a fast type.

[vinceroger69]

Re: Toshiba 24d1434db / Vestal 17IPS61-3 help

is there a upgrade for the SB5B0 diodes tom

[dooosuk]

Re: Toshiba 24d1434db / Vestal 17IPS61-3 help

Just to clear up some of the information above, are we saying:

Replace the UF5402 with a UF5408
Replace the SB5B0 with a SB5100 or similar (from this post https://www.badcaps.net/forum/showpo...5&postcount=48)

Thanks

[vinceroger69]

Re: Toshiba 24d1434db / Vestal 17IPS61-3 help

http://www.ebay.co.uk/itm/1722173855...%3AMEBIDX%3AIT
http://www.ebay.co.uk/itm/1717147546...%3AMEBIDX%3AIT

these are what i have just ordered as i have a set here needing the diodes changed.

[ReeceyBurger123]

Re: Toshiba 24d1434db / Vestal 17IPS61-3 help

http://www.ebay.co.uk/itm/1722173855...%3AMEBIDX%3AIT
http://www.ebay.co.uk/itm/1717147546...%3AMEBIDX%3AIT

these are what i have just ordered as i have a set here needing the diodes changed.

Cheers bud

[dooosuk]

Re: Toshiba 24d1434db / Vestal 17IPS61-3 help

All fixed with the new SB5100's.

Thanks chaps

[ReeceyBurger123]

Re: Toshiba 24d1434db / Vestal 17IPS61-3 help

Nice one

[GnobarEl]

Re: Toshiba 24d1434db / Vestal 17IPS61-3 help

Nice! Well done!