17PW20 PSU Working but no power lights on LCD

[tom66]

Re: 17PW20 PSU Working but no power lights on LCD

If they are reading a higher capacitance they could be leaky and this could be a sign of failure.

I'd estimate ~85-90% of these Vestel PSU failures are due to them.

[shepp]

Re: 17PW20 PSU Working but no power lights on LCD

Yeah, they could have failed again. Just check them on a cap meter.

there reading 34nf in circiut, both are, so gonna take them out tomorrow and retest because they should only be 15nf

[tom66]

Re: 17PW20 PSU Working but no power lights on LCD

Yeah, they could have failed again. Just check them on a cap meter.

[shepp]

Re: 17PW20 PSU Working but no power lights on LCD

ive changed them already, so they should be ok

[tom66]

Re: 17PW20 PSU Working but no power lights on LCD

See the tiny red caps near the big transformer. These tend to fail o/c.

[shepp]

Re: 17PW20 PSU Working but no power lights on LCD

i have noticed on some repair kits there is a voltage reg 5v, and C901 cap i havent replaced them, so for the sake of a couple of quid im gonna get the C901 cap first which is 4.7uf @ 50v then see if that does it, cant see voltage reg being faulty if im getting 5v stable,

24v comes on, then when the set powers back to standby when the 3v isnt present it shuts down the voltages so all the other voltages are fine.

only caps that will be left to replace will be the little ones, 100uf 16v etc, im determined to try and fix this one because ive replaced so many parts im sure it will last a long time, but saying that theres only so much on one tv you can take.....lol

[tom66]

Re: 17PW20 PSU Working but no power lights on LCD

The Vestel main board will do a self-test when first plugged in, if this fails it will go into "lock out" mode where it won't do anything. So, check the 24V peaks to 24V briefly. Honestly, these power supplies are so much trouble. I just replace them with a refurb 17PW15-8 or similar, those seem to last.

[shepp]

Re: 17PW20 PSU Working but no power lights on LCD

BAD NEWS the goodmans has returned with similar fault, although ive found that its something to do with the 3v yellow cable that goes to the back light, any ideas what to check or replace on this circuit? ive noticed that when the tv is brought out of standby there is no 3v to the back light all other voltages are stable, but when there is the 3v's the tv works ok but then switches off after about half an hour, it sounds like a bad cap but ive replaced all the main caps

[shepp]

Re: 17PW20 PSU Working but no power lights on LCD

37" up and running Saturday, just swopped main board and its working a treat

thanks guys for the input

gods knows how meny ive fixed now...thanks to this forum

[shepp]

Re: 17PW20 PSU Working but no power lights on LCD

same as but saving up for one of rusmikes ones he does a very good price shipped to the uk.

you got a link for it....so i can have a look

[vinceroger69]

Re: 17PW20 PSU Working but no power lights on LCD

same as but saving up for one of rusmikes ones he does a very good price shipped to the uk.

[shepp]

Re: 17PW20 PSU Working but no power lights on LCD

I need an esr meter really, I'm thinking about making one tho

[shepp]

Re: 17PW20 PSU Working but no power lights on LCD

I tend to find the easy fix ones i find cheap are always the hardest or unreparable ones,
although that 32in one i picked up a while ago with stand and remote for £30.00 was just 2 10uf or 100uf 450v caps on the inverter side so easy fix for once wish they was all that easy.

I tend to stay away from screen issue ones, like vert lines etc, so only had power board and invertor faults so far......thanks to this forum I've fixed all of them....o tell a lie I've got the 37" with main board that needs replacing

all but one tv cost me less than £55, and the one I bought for £80 cost more to fix than the others!

[vinceroger69]

Re: 17PW20 PSU Working but no power lights on LCD

I tend to find the easy fix ones i find cheap are always the hardest or unreparable ones,
although that 32in one i picked up a while ago with stand and remote for £30.00 was just 2 10uf or 100uf 450v caps on the inverter side so easy fix for once wish they was all that easy.

[shepp]

Re: 17PW20 PSU Working but no power lights on LCD

Picked up a 42" the other day with the same symptoms as the 32" so hoping it's the same fault....nice easy recap job!

[vinceroger69]

Re: 17PW20 PSU Working but no power lights on LCD

cool its nice when you mange to get a nonworking set up and running good luck with the 37in set.

[shepp]

Re: 17PW20 PSU Working but no power lights on LCD

all caps changed on the power board of the 32" Goodmans, out of the 13 i changed there was one bulging at the bottom....capxon cant remember the uf, but just tested for half hour and it hasnt gone off or any thing so another one done, just waiting for the main board for the 37" which i have had a slip through the door so got to pick up tomorrow from post office so fingers crossed that should work if not ill be back to report!

[shepp]

Re: 17PW20 PSU Working but no power lights on LCD

I've ordered the main board for the 37" and all the caps for the PSU on the 32" so I'll update when I've fitted and tested both TVs

Shame I didn't see the kit earlier cause I ordered the replacement caps for g-luxon caps yesterday, but ordered the Panasonic 15nf ones now, but will remember for future to look for the repair kits instead

Thanks tom

[tom66]

Re: 17PW20 PSU Working but no power lights on LCD

Looks fine but...

http://www.ebay.co.uk/itm/17pw20v1-v...8#ht_500wt_971

Might end up cheaper as it has a few other parts too.

[shepp]

Re: 17PW20 PSU Working but no power lights on LCD

will this do the 15nf ones?

http://www.ebay.co.uk/itm/PANASONIC-...item3a70f0a15f