Andersson TV + 17PW26-4 psu won't turn on?!

[Eriksson]

Hi guys..
Got an Andersson Tv 40" model A401FD.

So my problem is,
The TV won't turn on from standby and goes automatically back to standby after trying to turn it on. NOTICE that I got no picture what so ever. Only that the standby led disappears when I'm trying to turn it on.
The sound from the control panel on the tv works fine when I'm trying power/channel/volume buttons.

So I started doing some checks on the PSU
Can't find any caps damages.
The transistor/diod at the back side D879 is missing the middle pin?(3pins in total) tried to cold measure these outer two in diod mode which gave me just *beep*

My readings on the connector to Mainboard is
Pin 6 Standby 3v approx when turned off otherwise around 0.2
Pin 12 12v
Pin 16 3.3v
Pin 20 3.3v
Pin 24 0v
Pin 26 24v
These reading were measured when the TV was "on"

Would be really grateful for any help.
Thanks a lot in advance guys.

[Alastair E]

Re: Andersson TV + 17PW26-4 psu won't turn on?!

Check the PFC Voltage Across the main smoothing electrolytic, Should be around 400V

If its only 350 ish, the PFC Isnt working and the PSU will either Not start up, Or start Intermittently, but then run OK....

However--reading through your symptoms, It doesnt look like the PSU is actually at fault, as its starting and running, just that you have Sound but No Picture....

Check Backlights coming on or not and also the fuse on the T-Con board....

[budm]

Re: Andersson TV + 17PW26-4 psu won't turn on?!

https://www.badcaps.net/forum/showthread.php?t=39740

[Eriksson]

Re: Andersson TV + 17PW26-4 psu won't turn on?!

Psu

[Eriksson]

Re: Andersson TV + 17PW26-4 psu won't turn on?!

Motherboard

[Eriksson]

Re: Andersson TV + 17PW26-4 psu won't turn on?!

T-con board.
Sorry about reposting, didn't manage to upload multiple pictures in one reply for some reason..

Did test the fuse on the T-con board, it was ok. Not sure how to test the "PFC voltage" though.
However, why I do suspect the PSU is because when I try to turn the tv on, it goes automatically back to standby mode after about 10 seconds. I do not hear any audio at all besides from the clicks when I'm pressing the control panel. Don't think any backlights work either.
I also discovered that the same problem is still there when I remove the T-con board and try to turn the TV on.
Thanks in advance

[Eriksson]

Re: Andersson TV + 17PW26-4 psu won't turn on?!

Tried disconnecting backlighting today - still got the same problem. Is it possible that the control panel on the tv could be the problem?
When I disconnect the control panel, the led lamp just keep blinking slowly and in the same slow speed. Is it possible to "jump" the control panel? Doesn't care If it works or not. Still got the remote and I just want the tv to work.

[arizanotlari]

Re: Andersson TV + 17PW26-4 psu won't turn on?!

Hi.

unplug tcon and inverter board and start tv. if standby led working normal check tcon board, if still blink change r818 r819 r819 resistors to 620 kilohm (original 320K)

[arizanotlari]

Re: Andersson TV + 17PW26-4 psu won't turn on?!

Edit : r817 r818 r819 on pw26 board

[Eriksson]

Re: Andersson TV + 17PW26-4 psu won't turn on?!

Some update...
I've replaced following PSU components...
Fuse F800
Q803
Ic802
R829
R830
R817
R818
R819
C840
C801
C814
C892
-----------------------

Still no difference at all.. Not sure if it's the PSU or something else that's the problem. Please help!

[ReeceyBurger123]

Re: Andersson TV + 17PW26-4 psu won't turn on?!

Unplug the motherboard from the psu, and jumper the ps on pins then test and see if the psu starts any of the voltage rails, you may need a 100ohm + resistor.

[selldoor]

Re: Andersson TV + 17PW26-4 psu won't turn on?!

Need to establish if the screen flashes at all ? try in a dark room.
Also need a picture of the inverter board there are often fuses on it.

Did you try and look for a picture using a flashlight at angles on the screen.

Reeceyburger - dont know if you spotted it but early on he said he has sound
so at least some of the power supply is working.

[Eriksson]

Re: Andersson TV + 17PW26-4 psu won't turn on?!

As written before, when trying to start the TV, I have 3.3v, 5v, 12v and 24v. When the TV goes automatically back to standby mode, that is, after about 10 seconds, all voltage disappears.

Or did I misunderstand what you meant reeceyburger123?

Thanks for answer

[Eriksson]

Re: Andersson TV + 17PW26-4 psu won't turn on?!

Thanks for quick answer selleoor,
No picture at all, no backlighting what so ever,
I'll try to fix a picture of the inverter board. However,
When I have inverter board and Tcon board both removed, I've still got the same problem, that said, the only components connected is PSU, motherboard, standby led, speakers and side control panel (touch)....

[selldoor]

Re: Andersson TV + 17PW26-4 psu won't turn on?!

Sometimes when it is not all connected up the protection circuits kick in and close the power supply down. I will let Reeceyburger speak for himself but I think he is trying to test
just the power supply to see if it stays on. The jumper he mentions is to keep it on, in place of the signal from the mainboard

[budm]

Re: Andersson TV + 17PW26-4 psu won't turn on?!

Or check the DC Voltage on the PS_ON pin to see if it goes away.
Good clear pictures of the power supply board, both sides?

[Eriksson]

Re: Andersson TV + 17PW26-4 psu won't turn on?!

Thanks Guys,
Fuses on inverter ok.
I'll fix pictures in a couple of minutes and check things. What pin is ps_on?

And I did find a exactly similar problem which I'm having on YouTube, also with same PSU. Please give it a look. It is exactly similar situation for me.
http://m.youtube.com/watch?v=izJnFWLnzR0

I haven't replaced any of these caps because they all look ok, maybe I'll have to have a closer look.

[ReeceyBurger123]

Re: Andersson TV + 17PW26-4 psu won't turn on?!

As written before, when trying to start the TV, I have 3.3v, 5v, 12v and 24v. When the TV goes automatically back to standby mode, that is, after about 10 seconds, all voltage disappears.

Or did I misunderstand what you meant reeceyburger123?

Thanks for answer

What I was saying is you should test the psu with nothing hooked up to see if the voltages remain, if they do then the psu is likely not faulty.

[selldoor]

Re: Andersson TV + 17PW26-4 psu won't turn on?!

I haven't replaced any of these caps because they all look ok, maybe I'll have to have a closer look.

In usual vestel fashion the caps may be different values and/or in different positions - there are more caps on your board than in the video. The big one of the group may look slightly rounded but cant tell from the camera angle.
It is the one in the video with a hole in the top!!
They should be replaced with low esr good quality caps.

Are there no markings on either boards to say what the pins are.
Being a vestel - probably not!! PSon is likely to be one with 2-3 volts on it initially.