Samsung BN44-007676A power supply

[EazyBone]

Found my first burnt power supply!

Now I have no idea what I'm doing lol.

So I found where the most "burn" is and circled it from the component and I've been testing things and found that d9002c diode is good and testing .45 and it's connected to b9008. This is where more of the burn mark is shown on the board. First of all does anyone know what b9008 is? And second how am I to test this?

Is there something around the area that I should test? Kind of a big discoloration around this area.

I'm trying to replace pieces instead of the board and up my game bed tonight and this is as far as I got. Thanks

[CapLeaker]

Re: Samsung BN44-007676A power supply

As long as the power supply works, never mind the darkened area. This darkened spot men’s nothing, as the discolouration on the board is from the heat from the diodes, not from exploded parts (carbon).

[nomoresonys]

Re: Samsung BN44-007676A power supply

B9008 looks to be a ferrite bead, probably fine, tests same as a fuse or jumper, should show continuity.

[EazyBone]

Re: Samsung BN44-007676A power supply

Oh, I didn't mention sorry. The power supply doesn't work properly. It shows 8v varying where it should be 13v constant at all the pints. The stby is also about 2.4. but okay will keep tewtint board

[R_J]

Re: Samsung BN44-007676A power supply

Oh, I didn't mention sorry. The power supply doesn't work properly. It shows 8v varying where it should be 13v constant at all the pints. The stby is also about 2.4. but okay will keep tewtint board

This is normal, If you force the power ON, you will have a steady 13v.
Read the information on the corner of the board
STB:8v
On:13v
There is no separate STANDBY voltage, this is an always on power supply

[EazyBone]

Re: Samsung BN44-007676A power supply

This is normal, If you force the power ON, you will have a steady 13v.
Read the information on the corner of the board
STB:8v
On:13v
There is no separate STANDBY voltage, this is an always on power supply

Hmm I see maybe I was incorrect on this. How would I force the power on? Jump something?

[CapLeaker]

Re: Samsung BN44-007676A power supply

Plug in the backlights, while keeping the main board removed. Plug it in and the backlights should come on so does everything else.

You also can take a few 1k ohm resistors and jumps stby to PSon, BLon maybe some DIM.

[EazyBone]

Re: Samsung BN44-007676A power supply

This is normal, If you force the power ON, you will have a steady 13v.
Read the information on the corner of the board
STB:8v
On:13v
There is no separate STANDBY voltage, this is an always on power supply

Oops forgive me I did something wrong. It's not 8v on standby, it's actually 3.3 on standby and the voltage for each pin is jumping all around. Even where it says 8 v for standby that pin is also 3.3 ... 3.2... 3.4... 3.5... etc so yes something with power supply.

Back to testing board lol

[R_J]

Re: Samsung BN44-007676A power supply

It may be as simple as CM809 and CM814 are bad, as in open and not charging to keep the ic operating.
Check that D9001c and D9002c are ok and not shorted. If they are not shorted, check what voltage you get on D9001c Cathode, it could be around 330v but is likely less given the state of the 13v
Check the voltage across one of the main caps CP806 or CP807, this will tell you if the pfc circuit is working
Post the ic number of ICM801S It might be a FA6A20N or similar

[EazyBone]

Re: Samsung BN44-007676A power supply

Will check tonight!

[EazyBone]

Re: Samsung BN44-007676A power supply

It may be as simple as CM809 and CM814 are bad, as in open and not charging to keep the ic operating.
Check that D9001c and D9002c are ok and not shorted. If they are not shorted, check what voltage you get on D9001c Cathode, it could be around 330v but is likely less given the state of the 13v
Check the voltage across one of the main caps CP806 or CP807, this will tell you if the pfc circuit is working
Post the ic number of ICM801S It might be a FA6A20N or similar

Took out each capacitor from the board and checked capacitance and all are reading the correct uf within 5 percent.

Checked d9001/2 and not shorted.

Icm801 I have picture kind of hard to see as I had to scrape some silicone. Don't even know what this is lol.

Tested mosfets from drain to source in diode mode. Are the first two bad mosfets?
I been learning how to test them and shouldn't they be OL like others?

Mosfet cold side
MBRF10150CTL
Dm851c
Starts zero climbs to 3v slowly

Mosfetcold side
Dfrf10a60cta green
Dm853c
.434

Mosfetcold side
Dfrf10a60cta orange
Dm854c
OL

Mosfetcold side
3n50nz
Q9001c
OL

Mosfetcold side
3n50nz
Q9002c
OL

Mosfet hot
Kf9n50
Qm801cs
OL

Mosfet hot
Kf9n50
Qm803cs
OL

Two more mosfer cant read letters
Both OL hot

Next step anyone? And my mosfets are bad yes? YouTube doesn't answer me lol.
Also all the mosfets tested in continuity mode don't test short.

I'm gonna figure this out lol

Thanks all!!����️����������