Toshiba 40E200U1 Power Supply Not Turning On

[mmartell]

Ok this set has had intermittent shut down with squealing sound and then not able to turn back on for a period of time but was working when I sorta dropped it a little No damage but I notice now the power supply will not turn on.

I have working 5v Standby. Voltage at main filter cap is 170v. When I feed 5v to #pson there is no change.

Should there not be 5v on the #acd (ac-detect?) pin as I have nothing there.

[mmartell]

Re: Toshiba 40E200U1 Power Supply Not Turning On

Ok I'm pretty sure I should have 5v at #acd so how/where does that get generated ?

[freakaftr8]

Re: Toshiba 40E200U1 Power Supply Not Turning On

sounds like the one I had turned out to be a main board. It would stay on as long as I wanted to but as soon as I turned it off it would not power back on for a few days turned out the BGA flow on the bottom of the main processor was bad so I cooked it in the oven at 400 degrees for 10 minutes
Problems solved but unfortunately I melted the buttons on the side of the board. took some rework to fix those so I wouldn't advise it.

I was stumped myself and even tried a different power supply at first to find out that I was getting 5 volts standby so I was off to the main board.

[tom66]

Re: Toshiba 40E200U1 Power Supply Not Turning On

Missing AC detect might cause the set to not come out of standby - but it shouldn't prevent it actually starting. Maybe AC detect is only available when the PSU is running. I'd check the Vcc for the controller of those two FETs mounted on the heatsink and all output diodes on the power supply.

[mmartell]

Re: Toshiba 40E200U1 Power Supply Not Turning On

sounds like the one I had turned out to be a main board. It would stay on as long as I wanted to but as soon as I turned it off it would not power back on for a few days turned out the BGA flow on the bottom of the main processor was bad so I cooked it in the oven at 400 degrees for 10 minutes
Problems solved but unfortunately I melted the buttons on the side of the board. took some rework to fix those so I wouldn't advise it.

I was stumped myself and even tried a different power supply at first to find out that I was getting 5 volts standby so I was off to the main board.

I'm not discounting the possibility of a bad main board yet but I have jumped the pson with stb 5v and still no secondaries.

[mmartell]

Re: Toshiba 40E200U1 Power Supply Not Turning On

Missing AC detect might cause the set to not come out of standby - but it shouldn't prevent it actually starting. Maybe AC detect is only available when the PSU is running. I'd check the Vcc for the controller of those two FETs mounted on the heatsink and all output diodes on the power supply.

I'm confused, tom. I have the main board isolated and on my bench. When plugged on I get my 5vstb. When I jump pson I get no 12v and 24v. This is essentially coming out of standby, no ?

Earlier I measured vcc at the controller and got about 14v.

[freakaftr8]

Re: Toshiba 40E200U1 Power Supply Not Turning On

Try jumping BL_on at the same time

[mmartell]

Re: Toshiba 40E200U1 Power Supply Not Turning On

Don't even tell me that lol. Will try shortly...

[tom66]

Re: Toshiba 40E200U1 Power Supply Not Turning On

I'm confused, tom. I have the main board isolated and on my bench. When plugged on I get my 5vstb. When I jump pson I get no 12v and 24v. This is essentially coming out of standby, no ?

yes, what I mean is the AC detect might not work if 12V/24V are missing...

[budm]

Re: Toshiba 40E200U1 Power Supply Not Turning On

http://assets.shopjimmy.com/media/ca...1-bottom_1.jpg
Cehck the DC Voltage right at the two legs of C105 which is the filte cap for the VCC feeding the SMPS IC U101 for the 12V/24V.
The ACD sinal is used by the main board only, so you should be able to force on the power supply by itself to get the 12v/24v to run.
Please also get the P/N of U101.
The two main filter caps should have about 160VDC on each one of them, it is setup as the Voltage doubler.

[mmartell]

Re: Toshiba 40E200U1 Power Supply Not Turning On

Try jumping BL_on at the same time

Wait that *shouldn't* do anything because it's an output signal routed through the ps.

[mmartell]

Re: Toshiba 40E200U1 Power Supply Not Turning On

Hi bud, that is not my board.

My power ic is at U2, STR-A069. I have about 170v at both main filter caps.

[mmartell]

Re: Toshiba 40E200U1 Power Supply Not Turning On

Here's a couple pics of the underside.

[budm]

Re: Toshiba 40E200U1 Power Supply Not Turning On

Can I see the whole bottom side of the board?
It is funny that I typed in your board numbers PK101V1506I in SJ, the pictures do not match your board.

[mmartell]

Re: Toshiba 40E200U1 Power Supply Not Turning On

Ya I saw that too, maybe a different revision ??

Not at home now. I took a couple but they are not too good. I will post - maybe you can see something in them.

[budm]

Re: Toshiba 40E200U1 Power Supply Not Turning On

OK, we need to get the P/N of that SMPS IC (8-PIN) so we can check the VCC pin Voltage reading.

[mmartell]

Re: Toshiba 40E200U1 Power Supply Not Turning On

My mistake I thought the smps ic was on the topside.

I have the part number written down at home. Will be there shortly.

[mmartell]

Re: Toshiba 40E200U1 Power Supply Not Turning On

L6571
E9941

Made by ST

[mmartell]

Re: Toshiba 40E200U1 Power Supply Not Turning On

Freak you were %100 correct. Perhaps the #acd pin is an "ok" from the inverter because the backlights are on and secondary voltages are present by jumping #blon.

And since you were right about that I suspect you are right about the bga on the main board. Will investigate.

[freakaftr8]

Re: Toshiba 40E200U1 Power Supply Not Turning On

I checked over the board and tried to find any bad solder connections which led me to believe that it was the main processor it once I figured I had no other alternatives after I got the power supply to fire up the secondaries that's why I threw it in the oven of course this may not be a hundred percent repairable but for me it worked and have to get the TV to a charity with the remote telling them the buttons on the side of the TV don't work anymore lol.

of course I tried other alternatives first by replacing the EEPROM which didn't work and doing some voltage checks off the EEPROM led me suspecting that it was the main processor