Samsung UN55EH6000F Power issue

**CraigR** · 01-20-2022, 12:41 PM

I got in a Samsung UN55EH6000F with no power and blown fuse on the board (BN44-00499A) I found 3 bad mosfets and a blown resistor circled in the pictures. Now just putting power to the board and checking voltages I get what I need 13v then goes off and on over and over. I connected to TV and TV powers on with sound then off over and over again. I did not include pics of the TV since it is in the power board. So what would cause it to power on and off repeatedly? ?

**nomoresonys** · 01-20-2022, 07:33 PM

Check all the diodes and touch up any solder joints that look odd.

**CraigR** · 01-20-2022, 07:36 PM

Yep, went through all that before posting.

**R_J** · 01-20-2022, 07:51 PM

That looks like a gate drive resistor, I would check the zener diodes and the other resistors in that drive circuit.
One of the components you have circled is the standby ic, was it replaced as well?

**nomoresonys** · 01-20-2022, 08:21 PM

Quote:

Originally Posted by CraigR

Yep, went through all that before posting.

At least a few still look cracked to me.

**CraigR** · 01-26-2022, 02:08 PM

Quote:

Originally Posted by R_J

That looks like a gate drive resistor, I would check the zener diodes and the other resistors in that drive circuit.
One of the components you have circled is the standby ic, was it replaced as well?

Yes, it was replaced also.

**CraigR** · 01-26-2022, 02:38 PM

I found this mosfet (2 legs gone now) with nothing going threw it compared to other one with same number. Anybody know how I can get a good number to get another? WR N7 not coming up with anything on google.

**R_J** · 01-26-2022, 03:24 PM

What is the board location?

**dskall** · 01-26-2022, 03:30 PM

Looks to be an NPN. If it is sot-23
WR 2PD602R Si-npn GP, Sw, 60V, 500mA, 250mW, B=120..240, >160MHz SOT-23

If you have a component tester, just remove the other one and check it.

**diif** · 01-26-2022, 03:33 PM

**CraigR** · 01-26-2022, 03:47 PM

Quote:

Originally Posted by R_J

Might be 2SK322WR What is the board location?

ZDL802 so must be zener diode and not a mosfet? the N made me think N channel?

**lotas** · 01-26-2022, 04:04 PM

Bzx84c24-au

**R_J** · 01-26-2022, 04:04 PM

That looks correct, let me guess, they are in the gate circuit.

**lotas** · 01-26-2022, 04:23 PM

in the gate circuit

**CraigR** · 01-27-2022, 01:52 PM

Yep. Thanks for the number! I will order some up and get back with how it goes.

**CraigR** · 02-03-2022, 10:48 AM

UPDATE: Same thing. 13v then zero just keeps doing it over and over. I was looking it all over again and see a tiny crack in the big green thermister wtr15d050 but I get 8.3 ohms cold so not sure if the crack means damage or not?

**R_J** · 02-03-2022, 12:39 PM

What about the A5V is it changing as well?

**CraigR** · 02-03-2022, 01:07 PM

Quote:

Originally Posted by R_J

What about the A5V is it changing as well?

Yes it is.

**R_J** · 02-03-2022, 01:39 PM

Quote:

Originally Posted by CraigR

Yes it is.

The first thing I would try is to connect the PS_ON/OFF pin to ground, this should place the power supply in standby mode, then you can see if the standby voltage A5V is stable.
CNM803 pin 14 is PS_ON/OFF

**CraigR** · 02-03-2022, 02:12 PM

Quote:

Originally Posted by R_J

The first thing I would try is to connect the PS_ON/OFF pin to ground, this should place the power supply in standby mode, then you can see if the standby voltage A5V is stable.
CNM803 pin 14 is PS_ON/OFF

Zero volts 5 nor 13 when when PS_ON/OFF jumped to ground.

01-20-2022, 07:33 PM	#2
nomoresonys Badcaps Veteran Join Date: Jan 2013 City & State: midwest My Country: U.S. I'm a: Knowledge Seeker Posts: 7,628	Re: Samsung UN55EH6000F Power issue Check all the diodes and touch up any solder joints that look odd.

01-20-2022, 07:36 PM	#3
CraigR Badcaps Veteran Join Date: Dec 2013 City & State: Wisconsin My Country: USA I'm a: Knowledge Seeker Posts: 665	Re: Samsung UN55EH6000F Power issue Yep, went through all that before posting.

01-20-2022, 07:51 PM	#4
R_J Badcaps Veteran Join Date: Jun 2012 City & State: ☻ My Country: Canada I'm a: Professional Tech Posts: 7,962	Re: Samsung UN55EH6000F Power issue That looks like a gate drive resistor, I would check the zener diodes and the other resistors in that drive circuit. One of the components you have circled is the standby ic, was it replaced as well? Last edited by R_J; 01-20-2022 at 08:00 PM..

01-26-2022, 03:24 PM	#8
R_J Badcaps Veteran Join Date: Jun 2012 City & State: ☻ My Country: Canada I'm a: Professional Tech Posts: 7,962	Re: Samsung UN55EH6000F Power issue What is the board location? Last edited by R_J; 01-26-2022 at 04:06 PM..

01-26-2022, 03:30 PM	#9
dskall Badcaps Veteran Join Date: Oct 2016 City & State: Bakersfield ca. My Country: usa Line Voltage: 120VAC 60Hz I'm a: Knowledge Seeker Posts: 2,642	Re: Samsung UN55EH6000F Power issue Looks to be an NPN. If it is sot-23 WR 2PD602R Si-npn GP, Sw, 60V, 500mA, 250mW, B=120..240, >160MHz SOT-23 If you have a component tester, just remove the other one and check it. __________________ I assume no responsibility for any stupid suggestions I might post. Last edited by dskall; 01-26-2022 at 03:39 PM..

01-26-2022, 03:33 PM	#10
diif Badcaps Veteran Join Date: Feb 2014 City & State: Midlands My Country: England I'm a: Professional Tech Posts: 5,994	Re: Samsung UN55EH6000F Power issue .

01-26-2022, 04:04 PM	#13
R_J Badcaps Veteran Join Date: Jun 2012 City & State: ☻ My Country: Canada I'm a: Professional Tech Posts: 7,962	Re: Samsung UN55EH6000F Power issue That looks correct, let me guess, they are in the gate circuit.

01-27-2022, 01:52 PM	#15
CraigR Badcaps Veteran Join Date: Dec 2013 City & State: Wisconsin My Country: USA I'm a: Knowledge Seeker Posts: 665	Re: Samsung UN55EH6000F Power issue Yep. Thanks for the number! I will order some up and get back with how it goes.

02-03-2022, 10:48 AM	#16
CraigR Badcaps Veteran Join Date: Dec 2013 City & State: Wisconsin My Country: USA I'm a: Knowledge Seeker Posts: 665	Re: Samsung UN55EH6000F Power issue UPDATE: Same thing. 13v then zero just keeps doing it over and over. I was looking it all over again and see a tiny crack in the big green thermister wtr15d050 but I get 8.3 ohms cold so not sure if the crack means damage or not? Last edited by CraigR; 02-03-2022 at 10:57 AM..

02-03-2022, 12:39 PM	#17
R_J Badcaps Veteran Join Date: Jun 2012 City & State: ☻ My Country: Canada I'm a: Professional Tech Posts: 7,962	Re: Samsung UN55EH6000F Power issue What about the A5V is it changing as well?

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