Toshiba 32BV702B - another dead 17PW25-4

[abdekader]

Re: Toshiba 32BV702B - another dead 17PW25-4

I replaced all CAP but nothing new

the same problem

[tom66]

Re: Toshiba 32BV702B - another dead 17PW25-4

Diodes OK on secondary side?
These PSUs have a protect circuit. If main board tries to turn on main outputs (12V,24V) but they do not turn on, it will reset the 5V standby, which is a right pain in the ass to debug.
So I would check PS ON signal, and see why main outputs are not present, maybe for example shorted diode, bad controller IC, bad source resistor for FET, etc.

[abdekader]

Re: Toshiba 32BV702B - another dead 17PW25-4

thank you tom66

this some information

I replaced 7529 IC and all Diods in output and FET AND all Resistors around it but the same problem

where is the PS ON signal please ?

[tom66]

Re: Toshiba 32BV702B - another dead 17PW25-4

Well I don't have the solution, sorry!

These power supplies are a pain in the arse to debug and are terrible, giving various problems. The design is absolutely one of the worst I have ever encountered. It buzzes loudly, runs far too hot, and cooks output diodes. Why not go down to Vestel's R&D offices in Turkey and ask them why they produce such a piece of garbage which blows up now 4 times after 2,500 hours usage.

Even if you fix it it'll just die a year later.

[abdekader]

Re: Toshiba 32BV702B - another dead 17PW25-4

I replaced all tool kit OK

but the same

it isn't the one i have 10 PSu the same problem

[selldoor]

Re: Toshiba 32BV702B - another dead 17PW25-4

can you post a good clear picture of both sides of the power supply and close up of connectors

[abdekader]

Re: Toshiba 32BV702B - another dead 17PW25-4

the same problem (( I also think the standby controller is bad. I disconnected shorted FET and powered unit up with 100W bulb in series. Bulb does not light at low load. 5VSB jumps between 2.5~4V. Initially I suspected bad startup cap ))

i don't understand what's the solution to this problem please

[selldoor]

Re: Toshiba 32BV702B - another dead 17PW25-4

Abdekader -can you post a good clear picture of both sides of the power supply and close up of connectors.

With the fet out do the pads measure shorted or are they ok.

[abdekader]

Re: Toshiba 32BV702B - another dead 17PW25-4

this pictures







no short in board

I replaced all tool kit OK

but the same problem

[selldoor]

Re: Toshiba 32BV702B - another dead 17PW25-4

What is "tool kit"?

Have you tested the banks of diodes- may need to lift one leg.

EDIT - sorry I see you say you have already replaced them

I have attached your pictures so they dont disappear off the thread.

[vinceroger69]

Re: Toshiba 32BV702B - another dead 17PW25-4

post 7 in this thread tom had the same issue not sure if the ic solved it? maybe tom will remember.
https://www.badcaps.net/forum/showth...light=17PW25-4

[selldoor]

Re: Toshiba 32BV702B - another dead 17PW25-4

Thanks Vince was hoping Tom would look in but I know these boards get him annoyed.
Hopefully a dud diode will be found - I hope it hasnt blown his Fet already.

EDIT
Drat - I now see he has replaced them all already!!
Also see Tom has looked at it already and suggests he didnt fix it. So I havent much chance - and the translation problem
is a problem

[vinceroger69]

Re: Toshiba 32BV702B - another dead 17PW25-4

yes i missed that too about the controller ic being changed already i need to get out the habbit of only reading the last couple of posts and re read the whole thread to see whats been changed and hasnt.

tool kit? maybe repair parts kit for the 17PW25-4

[Alastair E]

Re: Toshiba 32BV702B - another dead 17PW25-4

Why not just replace the damned thing! They are Rubbish PSU's!

They are cheap to buy from parts suppliers--New here in UK. I dont bother fixing 'em anymore, just replace it.....

In Turkey, your home country,--where this Utter Crap is made-- should cost less than a curry!

[abdekader]

Re: Toshiba 32BV702B - another dead 17PW25-4

selldoor , ı replaced but this another one , the same problem ofcourse in both and 10 psu

sorry repair kit

[selldoor]

Re: Toshiba 32BV702B - another dead 17PW25-4

Was the psu you are trying to work already paired to the main board you are using?
Which TV set is it in?

[abdekader]

Re: Toshiba 32BV702B - another dead 17PW25-4

out system 5v ,3.3v flipflop

no 12v ,24v

in system Shows an error no power

[tom66]

Re: Toshiba 32BV702B - another dead 17PW25-4

Exactly what I found when the PS ON line is triggered but the PSU does not fire. Bloody confusing, it's a protection circuit which causes 5V/3.3V to dip. You need to find out why protection fires or why the main outputs do not work.