17pw26-4 psu

[hifiguy]

Hi
I have a Bush TV in for repair with the standby light flashing rapidly. I've fitted the repair kit ie. C878, 801, 892, 817 and IC829 but the fault is the same.
Anyone had this? Or any tips?
Help would be very much appreciated.
Thanks
Geoff

[PlainBill]

Re: 17pw26-4 psu

Hi
I have a Bush TV in for repair with the standby light flashing rapidly. I've fitted the repair kit ie. C878, 801, 892, 817 and IC829 but the fault is the same.
Anyone had this? Or any tips?
Help would be very much appreciated.
Thanks
Geoff

Is the standby light flashing in any discernible pattern? Some manufacturers use this as a means of displaying error codes. Others just flash a particular color (standby / power, etc) to indicate a problem.

Have you checked the output voltages of the power supply?

Elektrotanya.com has many service manuals; searching the model number of the TV might help; the model number of the power supply doesn't generate any hits.

PlainBill

[hifiguy]

Re: 17pw26-4 psu

Is the standby light flashing in any discernible pattern? Some manufacturers use this as a means of displaying error codes. Others just flash a particular color (standby / power, etc) to indicate a problem.

Have you checked the output voltages of the power supply?

Elektrotanya.com has many service manuals; searching the model number of the TV might help; the model number of the power supply doesn't generate any hits.

PlainBill

Hey Plainbill,
Thanks for a speedy response.
The standby light simply flashes with no pattern (I know what you mean about fault codes). So far I haven't found a schematic but I'm hopeful. This type (vestel) psu's are prone to failure as I'm sure you know and usually caps are to blame although I have known one or two exceptions and I'm guessing this one.
Thanks again. I'll check at Elektrotanya.com.

Geoff

[tom66]

Re: 17pw26-4 psu

I've tried repairing a 17PW20.1 with an identical fault. LED flashes 2-3 times a second.

My debugging so far has pointed entirely to the power supply; the rails are too low (12V measures ~4.5V, for example). At the moment, it's in the corner of my room, waiting for repair.

The main board tells the power supply to come on, however the rails are too low, so it shuts down. The cycle repeats until power is disconnected. The main board is what is telling the PSU to go on/off and is what is causing the rail to be so low, but I don't think it's at fault itself.

[hifiguy]

Re: 17pw26-4 psu

I've tried repairing a 17PW20.1 with an identical fault. LED flashes 2-3 times a second.

My debugging so far has pointed entirely to the power supply; the rails are too low (12V measures ~4.5V, for example). At the moment, it's in the corner of my room, waiting for repair.

The main board tells the power supply to come on, however the rails are too low, so it shuts down. The cycle repeats until power is disconnected. The main board is what is telling the PSU to go on/off and is what is causing the rail to be so low, but I don't think it's at fault itself.

Hi Tom
Some progress but no real advance (hmmm) Having changed caps and reg I've found D893 s/c. Changed it but the fault remains. I'm searching for service info for the whole set but that's not proving easy.
Cheers
Geoff

[tom66]

Re: 17pw26-4 psu

Schematic for 17PW22 (the name of the chassis, the PSU itself is 17PW20.1) available on eserviceinfo; just search for "17PW22".

I've got one for a Sanyo TV, somewhere....

[hifiguy]

Re: 17pw26-4 psu

Tom, I found the schematic you directed me to. Thanks for that. The diagram doesn't seem to agree with the psu I'm working on. The search continues.

Thanks again
Geoff

[tom66]

Re: 17pw26-4 psu

Tom, I found the schematic you directed me to. Thanks for that. The diagram doesn't seem to agree with the psu I'm working on. The search continues.

Thanks again
Geoff

In my case the schematic was okay, but the PCB layout was completely different.

[hifiguy]

Re: 17pw26-4 psu

Ok got the cure.

D881 (893) s/c. Print side there is a 0 ohm smd link o/c. Replaced and now all ok.

[tom66]

Re: 17pw26-4 psu

Ok got the cure.

D881 (893) s/c. Print side there is a 0 ohm smd link o/c. Replaced and now all ok.

Maybe I should check that on mine.

[hifiguy]

Re: 17pw26-4 psu

Good luck Tom
I noted that on the diagram it showed two 2k2's feeding the cathode but the board I've got just had the one 0 ohm at R1036.

[nopain77]

Re: 17pw26-4 psu

Hello,
Got the same thing on a Telefunken T40R882FHD with powersupply 17PW26-4
Error was : On (Red) and Standby LED (blue) blinking alternately.TV stuck in standby.
Replacing the D881 with another ultrafast rectifier did it.

Thanks for post it.

[blado1984]

Re: 17pw26-4 psu

Hi guys just a quick question. I have this issue with my alba tv and 17pw26-4 board. Started off as flashing red and blue and eventually ended with tv completely stuck in standby (condtant blue light). I have replaced c801 and c892 no change so replaced d893/d881 still no change. When i press touchpad there is an audible *beep* but light stays blue. Using thr remote seems to do absolutely nothing. Just wondering that seeing as i am now past the flashing red/blue stage and stuck on constant blue does this mean total board failure? Thanks in advance

[abdekader]

Re: 17pw26-4 psu

My 17pw26-4 , no 12v why?

5v ok
3.3 ok

what's the problems ?

[tom66]

Re: 17pw26-4 psu

Any 24V?

[abdekader]

Re: 17pw26-4 psu

No 12v , no 24v

[tom66]

Re: 17pw26-4 psu

Got PSON signal? What is VCC at FAN7711 for the main outputs? Do you have about 390V at the 450V capacitor?

[abdekader]

Re: 17pw26-4 psu

Pson where

in capasitor 306v

in vcc 7711 about 14 but flip flop

[promo7uk]

Re: 17pw26-4 psu

HI REASON FOR NO 12V & 24V IS FAULTY DIODE..

COMMON PROBLEM ON THESE POWER SUPPLYS IS FEED DIODE GOES OPEN CIRCUIT MUST REPLACE WITH SAME.UF5404

http://www.ebay.co.uk/itm/UF5404-DIO...item2ec783c7b5

17PW26-4 FAULT NO 12V NO 24V ,,,,, DIODE PLACEMENT,

[promo7uk]

Re: 17pw26-4 psu

Heres faulty diode mate,, let me know outcome thanks lee