Samsung U32D970 PSU blown up (Identifying Parts)

[Fr3shGy]

Hi, my U32D970 PSU (BN44-00786A) has blown up. It went out with a loud bang.

One of the N-Channel Mosfets (OM802C) caused a short and fried the trace and its components connecting to one of the pins of the 6A01 IC.

I need help to identify 2 SMD resistors which lost their markings
highlighted in picture 3 (RM812 and RM808).

Maybe someone can help me identify them, has a schematic or can give me some advice. would be much appreciated.

6A01 IC datasheet ( https://www.fujielectric.com/company...4-245-2013.pdf )

[lotas]

Re: Samsung U32D970 PSU blown up (Identifying Parts)

The photo shows that other resistors also burned out, rather, these diodes in the sot23 package also suffered.

[Fr3shGy]

Re: Samsung U32D970 PSU blown up (Identifying Parts)

Yes both traces got damage. i am going to change every part on each trace.

i am not certain what values these resistors have.

[lotas]

Re: Samsung U32D970 PSU blown up (Identifying Parts)

RM812 should be 10kOhm (103), RM 808 is a low ohm resistor.

[lotas]

Re: Samsung U32D970 PSU blown up (Identifying Parts)

RM805 = RM809
RM806 = RM812
RM804 = RM808
DM805 = DM811

Please refer to this diagram. And you will have to replace the second mosfet (rather, it is also not working.

[Fr3shGy]

Re: Samsung U32D970 PSU blown up (Identifying Parts)

Thank you all for the help. I am currently in the process of replacing and ordering the new components.

I am going to replace both mosfets as lotas has suggested. the broken ones are:

Fairchild FDPF18N50T
https://www.mouser.com/datasheet/2/1...0T-1008232.pdf

Can i replace them with mosfets which have a lower "continuous drain current" rating like APT9N70's? Or are they likely to go "bang" as well?

APT9N70
https://aosmd.com/sites/default/file...ts/AOT9N70.pdf

And is a 6A01 replaceable with a 6A21? i can't find a datasheet for the 6A21.

[Fr3shGy]

Re: Samsung U32D970 PSU blown up (Identifying Parts)

so after waiting ages for the parts, they finally all arrived.

currently replacing the 6A01 and the resistors. i found out that the capacitor CM804 gives me no reading inside nor outside the circuit and needs to be replaced.

Does someone has the value of CM804?

[lotas]

Re: Samsung U32D970 PSU blown up (Identifying Parts)

Here is an approximate circuit from this series, it costs 0.1mFx50v.

[lotas]

Re: Samsung U32D970 PSU blown up (Identifying Parts)

On this diagram, it is designated as C110, but there is no face value for it.

[Fr3shGy]

Re: Samsung U32D970 PSU blown up (Identifying Parts)

thank you for helping me with this. i only had a 10mf capacitor laying around but i ordered a full set of them with lower values. for now i replaced the cap with the 10mf one.

I am getting weird readings. the second mosfet does not turn on (i marked some readings in the picture).

I probably need to replace C820 aswell because the 11V does not pass through. as soon as i get the replacement caps i will make a more detailed overview of the readings i get.

[Fr3shGy]

BN44-00786A no power/no standby

I already posted a month ago about broken components on my BN44-00786A PSU that i replaced.

Took me ages to receive all the missing parts.

I replaced the purple marked components in picture 1 mainly the LO and HO line components, the components at the VW line, both mosfets and the IC.

I attached a picture with all the measurements i get currently.

1.VCC is sitting around 1.8kohms and puts out 11,28V
2.LO output gives me flat 0V therefore i get no voltage at the gate of the mosfet.
3.The UP801 that is a (SPC7011F / FA5965) receives 0V at the VCC pin.

Am i right that the VCC output voltage of the SMPS controller (FA6A01) should be at around 13,5V and because its at 11V it does not startup?

Does the VCC of the 6A01 supply the UP801 with power?

(I attached some pictures and similar schematics)
First Post: https://www.badcaps.net/forum/showthread.php?t=117242