Toshiba 32BV500B fault - Vestel 17PW26-4

[orbiter]

Re: Toshiba 32BV500B fault - Vestel 17PW26-4

Your right vince 1n5408 is higher spec but far slower.. Wonder if that could be the problem.

[vinceroger69]

Re: Toshiba 32BV500B fault - Vestel 17PW26-4

ive seen a few threads where people have fitted the wrong one and its caused issues so certainly wort replacing with a ultra fast one.

[dick_barton]

Re: Toshiba 32BV500B fault - Vestel 17PW26-4

UFxxxx should be replaced by UFxxxx the standard INxxxx are not up to the speed required and cause all sort of problems. They may have the voltage/current but not rectifying speed.

[orbiter]

Re: Toshiba 32BV500B fault - Vestel 17PW26-4

Ok thanks guys I'll order some UF5402 and some UF5404 too. Hopefully be here tomorrow from RS

[orbiter]

Re: Toshiba 32BV500B fault - Vestel 17PW26-4

Still no go fellas... New uf5404 fitted but made no difference. I've also changed the soic8 FAN IC on the smd side of the PCB and as far as I'm aware have checked almost everything else too. In some cases removing many components to test them were necessary.

Any more ideas on this please guys?.

Thanks

[dskall]

Re: Toshiba 32BV500B fault - Vestel 17PW26-4

Hi guys,

Sorry for not responding sooner, for some reason I did't get notification that there were any replies
even though I am subbed to the thread and instant notifications are set to ON.

Anyway.. I've reaplced DL321 and there's no change anywhere.

@dickbarton.. I've just tried whast you suggested but there still no 12/24v

@vince.. Thanks for that .pdf it's very helpful.

pin 4 =8v
pin 6 =2.5
pin 13 =0.14v
pin 14 =5v
pin 15 = 3.3v
pin 16 =3.3
pin 15/17/19/21 =0.2v
pin 18/20/22 =0.4v
pin 25 = 0.14v
pin 26/28 =0.14v

Is there a way that these PSU's can be powered without the mainboard connected guys?

Thank you

Are these the voltages you got when you jumped to pin 6 with mainboard disconnected? I ask because of your question above. (Is there a way that these PSU's can be powered without the mainboard connected guys?)

[dick_barton]

Re: Toshiba 32BV500B fault - Vestel 17PW26-4

Check the grey capacitor C878 which ReeceyBurger123 has reported as a fault on these power supplies. It's the grey one by the transformer between the two red circles on your first photo.

Also looking at the information provided by VinceRoger69 "the Vestel PSU Training Manual" for testing the power supply. It looks like you have to jump ST_BY (Pin6) to GND as shown on page 19.

[orbiter]

Re: Toshiba 32BV500B fault - Vestel 17PW26-4

Are these the voltages you got when you jumped to pin 6 with mainboard disconnected? I ask because of your question above. (Is there a way that these PSU's can be powered without the mainboard connected guys?)

No mate.. Sorry for confusion.. Mainboard was connected when I got these voltages... I just wasn't sure if MB needed to be hooked-up as I would have liked to test the PSU separately the bench but it seems best if everything is connected. Thanks though

Check the grey capacitor C878 which ReeceyBurger123 has reported as a fault on these power supplies. It's the grey one by the transformer between the two red circles on your first photo.

Also looking at the information provided by VinceRoger69 "the Vestel PSU Training Manual" for testing the power supply. It looks like you have to jump ST_BY (Pin6) to GND as shown on page 19.

C878 is good. Voltages are just as in my previous post even if STBY is gnd'd

[orbiter]

Re: Toshiba 32BV500B fault - Vestel 17PW26-4

Here is my voltages again compared to correct specs

[dick_barton]

Re: Toshiba 32BV500B fault - Vestel 17PW26-4

With the mainboard disconnected short ST_BY to 0V ?

[dskall]

Re: Toshiba 32BV500B fault - Vestel 17PW26-4

As pin 6 has voltage in standby it will have to be pulled to ground to turn on power supply.

[orbiter]

Re: Toshiba 32BV500B fault - Vestel 17PW26-4

Just me being stupid there... I just needed to short the main switch PL815. The voltages albeit the wrong ones show up after that and I can here the psu clicking. I guess PFC is trying to kick it on?

I got real problems though.. Here's my 3.3 & 5v rails too.. The 3.3v looks ok however there's still a light drop seemingly as the PSU tries to start.. But the 5v is all over the show dropping to 2.7 volts each time I assume start up attempts are made. So it seems now I've got a dodgy 5v rail AND no 12/24v






Thanks for the advice so far guys

[dick_barton]

Re: Toshiba 32BV500B fault - Vestel 17PW26-4

I cannot tell from the photo's how much the 5V is dropping and that looks like the capacitors are not filtering the dc voltage.
You also say no 12/24 but had you shorted ST_BY to 0V

[orbiter]

Re: Toshiba 32BV500B fault - Vestel 17PW26-4

Hi.. 5v rail is dropping to about 2.7v seemingly everytime the psu tries to start? (Better pics below) .. Yes 12/24v was shorted to gnd

Did you see my voltage chart above dickbarton? I posted immediately when you last replied so not sure if you saw it.


http://www.mediafire.com/view/4o7sm5ip78e4vdu/1.jpg

http://www.mediafire.com/view/2mf5iky27afxvw0/2.jpg

[dskall]

Re: Toshiba 32BV500B fault - Vestel 17PW26-4

Which is pl815? You maybe shorting 5v to ground causing it to go into protection.

[orbiter]

Re: Toshiba 32BV500B fault - Vestel 17PW26-4

Which is pl815? You maybe shorting 5v to ground causing it to go into protection.

Hi.. PL815 is just the pin header connector on the psu that connects to an on/off switch at the back of the tv.

[dskall]

Re: Toshiba 32BV500B fault - Vestel 17PW26-4

Is it clicking in standby?, when trying to power it on?, or with pin 6 grounded?

[dick_barton]

Re: Toshiba 32BV500B fault - Vestel 17PW26-4

Hi.. 5v rail is dropping to about 2.7v seemingly everytime the psu tries to start? (Better pics below) .. Yes 12/24v was shorted to gnd

Did you see my voltage chart above dickbarton? I posted immediately when you last replied so not sure if you saw it.


http://www.mediafire.com/view/4o7sm5ip78e4vdu/1.jpg

http://www.mediafire.com/view/2mf5iky27afxvw0/2.jpg

If your referring to post #29 then St_BY is not at OV so it cannot be shorted to 0V. So perhaps you are shorting the wrong pin and that is why the 5V is switching on and off.
The scope pictures are excellent but too small to read the scale so cannot tell if it was dropping in millivolts or Volts.

[orbiter]

Re: Toshiba 32BV500B fault - Vestel 17PW26-4

Is it clicking in standby?, when trying to power it on?, or with pin 6 grounded?

Only when I apply power to the PSU it sounds like the PFC area is ticking a couple of times a second.. the ticking does not seem consistently timed though.. I also noticed that the ticking seemed
to stop when I was measuring R815 adjacent to IC802 (FAN7529) ... IC802 has been replaced.

With the oscilloscope attached to the AC side of the PSU I can see the pulses created by this ticking in the waveform.

[dskall]

Re: Toshiba 32BV500B fault - Vestel 17PW26-4

This is all happening in standby?