17pw26-4 psu

[promo7uk]

Re: 17pw26-4 psu

Also heres diagram u were looking for,

[eri]

Re: 17pw26-4 psu

that diode ends with a 402 in my pw26-4 v1.0 and i am not sure if it is the right one

[eri]

Re: 17pw26-4 psu

well my prob is a have a FInlux tv 32FLD850h model with this psu and the symptoms are blue light , when i click tu turn ON in the tv buttons it makes the clicking sound but no turn on signs if any one can help would be great
sry for my bad english...
thanks in advance

[promo7uk]

Re: 17pw26-4 psu

yes mate 402 diode is lower amps and voltage than the 404 ,, these tvs should have been fitted with higher rating diode from the start but was not.. and the amps the psu kicks out to 24v 12v is higher than the 402 diode can take when gets hot takes alot of shit to be fair, so better using a 404...higher voltage higher amps rating, than 402..also if diode open circuit check r1036 surface mount should be 0 ohms. if not its taken that out as well.

[robinbrighouse@hotmail.co]

Re: 17pw26-4 psu

There's too many lines, squiggles and heiroglyphics for me! looks pretty though!

[BenTennyson]

Re: 17pw26-4 psu

Another Vestel fault here! These things seem to be the spawn of the devil.
Its a 17pw26-4 rev1 from a Telefunken T37P884 FHD 100 DVB-T.
(Schematic PDF for this particular PSU is here -> )

The TV set started out with having an extreme corrupt picture: Moving, distorted multicolored garbage, arranged in horizontal lines. The upper 1/8th of the picture was okay, the rest corrupt. After a day of probing and guessing, the TV set resigned to only go orange light for 15 seconds, then go to standby again.
According to some training manual on Scribd, the PSU should be in full-on mode when the signal line from the CPU (PL816, pin 6) is 0V so I just took it out of the case and tested without the mainboard (bridged upper and lower screw holes since the lower left area seems to be grounded trough the chassis only).

C819 Voltage is semi-stable, fluctuating between 398~399v
3,3v and 5,5v standby and 3,3/5,5v RUN voltages are rock solid, as well as the 24v line. No fluctuations here. BUT:
After Q827, +12V_BO and +12V both only measure 10v, sometimes going up to 12 but not for long.
I can't get a proper reading on pin 15 of TR810, since I only have a trashy five bucks digital multimeter, which is measunring 24,5V AC on that pin (+12SV).

According to these measurements, I presume that Q827 is failing. Agree?
Is it advisable to replace it with same type (STPS_3P_10L60CFP) or is there a better alternative?

[ReeceyBurger123]

Re: 17pw26-4 psu

I would say so or the controller for it have you checked all the small caps as well if one of them fails it can throw the controller off ?

[BenTennyson]

Re: 17pw26-4 psu

I replaced C851, C863 (12v rail) and C850 in the 24v rail with new caps instantly even before taking the voltages because they were bulged, although I replaced the caps in the 12v rail with 50v rated ones instead of 16v.
Should I check all the caps on the primary side of TR810 too?

Btw when you say 'controller', are you referring to IC830? Wouldn't the 24v rail be affected too if IC830 was glitchy?

Sorry if these questions sound stupid, I'm still learning. And this is my first try at a PSU.

[ReeceyBurger123]

Re: 17pw26-4 psu

Yes check the smaller side primary caps. Also I believe that the 24v rail is ran on a separate winding and controller for these. Let me check.

[BenTennyson]

Re: 17pw26-4 psu

Looks like this PSU has already been fiddled with before. I just noticed that Q827 in this PSU is an STPS20S100CFP
instead of a STPS_3P_10L60CFP like listed in the schematics. Hard to imagine that this one just failed like that. I will check the rest of the caps tomorrow.

[ReeceyBurger123]

Re: 17pw26-4 psu

It might not have been Vestel have well over 100 different schematics and designs for this board, they just throw whatever parts they have on the Pcb to get it to work.

[BenTennyson]

Re: 17pw26-4 psu

Ok now while I was probing the caps, the PSU is back to never switch on the running power rails at all. 5V STBY voltage is fluctuating heavily.

C892 never reaches 12v, which it SHOULD, according to this datasheet for IC806

The voltage on C892 fluctuates between 6-11volts

[BenTennyson]

Re: 17pw26-4 psu

PSU working with stable rails, TVset turns on but still has horizontal lines/picture corruption. Looks like the mainboard is borked.

[ReeceyBurger123]

Re: 17pw26-4 psu

Let me guess LG panel ? Also what did you do to fix Psu ?

[BenTennyson]

Re: 17pw26-4 psu

Quick solution: Bought a good one on ebay, because I've not enough time left to mingle around with this tv. I'll keep the faulty PSU and report back here if I can bring it to life again. Oh and yeah, its an LG panel. I witnessed something: The picture corruption goes away if I let it sit turned on for a few minutes. It continued to run flawlessly for a few hours until I put it into standby again. This morning I verified this, it showed the exact same behavior. Horizontal corruptions which vanished after a few minutes. Also measured the power rails of the PSU under load directly on the mainboard, everything stable. Voltages on the smaller two caps on the mobo fluctuate between 6-7volts. I dont know if that is ok, cant find schematics for that board. The caps are new, I replaced them before fiddling with the faulty PSU.

~~uploaded a video so you can actually see what I'm talking about:
https://youtu.be/Mj9qVfbir1c

Note how the upper few rows of pixels are always good. The board seems to desynch from the HDMI-signal for a second inbetween.

[ReeceyBurger123]

Re: 17pw26-4 psu

Ive had that on them 37LC panels so has user Dick Barton I was able to sort mine by replacing the ribbon cables going from the Tcon to the panel but he never sorted his I also had another which I couldn't sort. I cant help much sorry lets see what others think.

[BenTennyson]

Re: 17pw26-4 psu

I think I'll open a new thread about this issue since this isnt about the PSU anymore. Thread-hijacking is a bad habit of mine >_>