problem with psu in Samsung 32"

[Mikeyboy2007]

Hi there guys i have a Samsung LE32A457C1D which has the BN44-00214A PSU, when i first got the tv i noticed a burn / bulge mark on the back of the tv but when i popped off the back i nnoticed it is the big cap that is causing this, not too sure whether to switch tv on or not, does anyone know what could be the issue ?

[Mikeyboy2007]

Re: problem with psu in Samsung 32"

https://drive.google.com/open?id=0B8...ZnM&authuser=0

https://drive.google.com/open?id=0B8...TEE&authuser=0

https://drive.google.com/open?id=0B8...dlE&authuser=0

https://drive.google.com/open?id=0B8...NnM&authuser=0

https://drive.google.com/open?id=0B8...eG8&authuser=0

[Mikeyboy2007]

Re: problem with psu in Samsung 32"

Can anyone see the pictures in those links ?

[vinceroger69]

Re: problem with psu in Samsung 32"

Yes pictures work ok but still better to add as atachments if you can just in case google drive link does not work in future. I would remove that capacitor measure height/width and order a new one certainly looks like its got hot.

[flocko]

Re: problem with psu in Samsung 32"

Also remove all the brown glue crap from the board as this goes conductive and will short components out

[Mikeyboy2007]

Re: problem with psu in Samsung 32"

ok will order one and remove all the glue and let you guys know how it goes when replaced.

[ben7]

Re: problem with psu in Samsung 32"

Yep that capacitor let go and go so hot it melted the back cover!

I wonder what made it go like that....must have spewed a lot of stinky smelling steam!

I'd also suggest that you replace all the other electrolytic capacitors on this PSU, they are known to fail.

-Ben

[budm]

Re: problem with psu in Samsung 32"

Check that blue disc cap next to that big cap also, looks like the glue already turned conductive and the legs may be eaten away.

[Mikeyboy2007]

Re: problem with psu in Samsung 32"

Yep that capacitor let go and go so hot it melted the back cover!

I wonder what made it go like that....must have spewed a lot of stinky smelling steam!

I'd also suggest that you replace all the other electrolytic capacitors on this PSU, they are known to fail.

-Ben

Check that blue disc cap next to that big cap also, looks like the glue already turned conductive and the legs may be eaten away.

i most always replace the capacitors on these boards, never had to change the big one though, and i will double check that budm.

[katinkapicinyke]

Re: problem with psu in Samsung 32"

Hi All,
Sorry to resurrect such an ancient topic but dealing with an issue on the same model (Samsung LE32A457C1D) with the same PSU board. Did checks on the cold side of the PSU board, no sign of the 12V+ outputs (on turning on I get the same 5 red LED flashes and then nothing). That dreadful glue was all over QB802 and CP811, de-soldered QB802 (Fairchild D526-Y NPN transistor maybe?) and removed the glue, however the transistor test appears to be failing between B (with positive probe) towards E (negative probe) and C (negative probe) in diode mode with my super basic MM.
Can I order a D526-Y off from Aliexpress for a few bucks and try replacing that on its own?
Also, I'm measuring 84.2 uF for CP811 (schematics suggest 47uF...) but my MM is quite a cheap one, could the capacitor ok and just the meter off?
Is there anything else worth checking around which usually goes at the same time when QB802 is blown?
2nd post only, please be gentle but any suggestion would be appreciated!

[neilc6]

Re: problem with psu in Samsung 32"

If you search BN44-00214A, you will find a full page of posts for this board.

[nomoresonys]

Re: problem with psu in Samsung 32"

Maybe check some new batteries with your meter to check it for accuracy.

[budm]

Re: problem with psu in Samsung 32"

1) Can I see straight shot pictures of top and bottom side of YOUR board?
2) What Voltage do you get on E, C, and B of the QB802 if you put the Transistor back in place?
3) You said you do not get 12V, how about the 24v?
4) There will be no 12V or 24V if PS-ON is not present, so do you have PS-ON control Voltage?

[katinkapicinyke]

Re: problem with psu in Samsung 32"

First of all, thank you for all the above suggestions, much appreciated.

I've got a 1k resistor installed between SB and PS pins on CNM802, still no output on 12V/24V rails (I can measure 5.2V on the SB, also around 4V on PS once it is connected with the resistor).

With the above jumper in place, I'm only measuring about 324-330V on the big cap (CP803).

With the above jumper in place, I'm getting the following on QB802 (relative to HOT side GND of CP803):
Base:16.15V
Collector:23.9V
Emitter:0.04V

without the above jumper in place, I'm getting the following on QB802 (relative to HOT side GND of CP803):
Base:0.4V
Collector:26.33V
Emitter:0.2V

Once again, thanks for your time while looking into this.

[katinkapicinyke]

Re: problem with psu in Samsung 32"

First of all, thank you for all the above suggestions, much appreciated.

I've got a 1k resistor installed between SB and PS pins on CNM802, still no output on 12V/24V rails (I can measure 5.2V on the SB, also around 4V on PS once it is connected with the resistor).

With the above jumper in place, I'm only measuring about 324-330V on the big cap (CP803).

With the above jumper in place, I'm getting the following on QB802 (relative to HOT side GND of CP803):
Base:16.15V
Collector:23.9V
Emitter:0.04V

without the above jumper in place, I'm getting the following on QB802 (relative to HOT side GND of CP803):
Base:0.4V
Collector:26.33V
Emitter:0.2V

Once again, thanks for your time while looking into this.

One more thing please, with the mainboard, TCON and inverter connected I get 3.3V of SB constantly (would I be correct assuming logical HIGH sent back from the mainboard?) while powered up, it drops only for a mere second, so like goes to logical LOW (0V) and then back to 3.3V.

[katinkapicinyke]

Re: problem with psu in Samsung 32"

If you search BN44-00214A, you will find a full page of posts for this board.

Also, thank you for your suggestion, I read the below but found them inconclusive in my case, almost appeared to me as SMPS fault on mine with no obvious symptom.
https://www.badcaps.net/forum/showth...ht=BN44-00214A
https://www.badcaps.net/forum/showth...ht=BN44-00214A

[katinkapicinyke]

Re: problem with psu in Samsung 32"

Maybe check some new batteries with your meter to check it for accuracy.

Thank you, just did that but appears to me the same outcome when measuring that elco capacitor.

[nomoresonys]

Re: problem with psu in Samsung 32"

Check DB801,DB802.

[R_J]

Re: problem with psu in Samsung 32"

You are on the right track,
Base:16.15V
Collector:23.9V
Emitter:0.04V
The emitter voltage is missing, either due to an open QB802 or you have too much of a load on the M_VCC line. Check the resistance across CP811, this will give an idea of where the problem is.
You could have a bad ICP801S, or bad ICM801, or it is possible CP811, CP805, CM807, CM814 are shorted

[katinkapicinyke]

Re: problem with psu in Samsung 32"

You are on the right track,
Base:16.15V
Collector:23.9V
Emitter:0.04V
The emitter voltage is missing, either due to an open QB802 or you have too much of a load on the M_VCC line. Check the resistance across CP811, this will give an idea of where the problem is.
You could have a bad ICP801S, or bad ICM801, or it is possible CP811, CP805, CM807, CM814 are shorted

Thank you, I can see no short on CP811, CP805 (took me some time to find, little SMD bugger!), neither on CP805, CM807, nor on CM814.

The resistance between the two legs of CP811 is around 4.5K Ohm, give or take due to my meters tolerance.