Samsung Odyssey G9 (c49g95tssr) no picture or backlight. Power LED shows

[lotas]

yes sir. 10ohms and beeps in continuity mode.

i did a continuity check of 'B' side of the blown fuse and it beeps when i touch either side of C907. Are we getting close?

But it should not show 10 Ohm, unless it is paralleled to this resistor.

[lotas]

ive tried to draw the continuity lines, at point A, there is continuity everywhere with that side of the fuse. on the other end where the white line just 'ends' there is pretty much continuity on nearly everywhere on that side of the board so i stopped drawing the line

What I don’t understand is that continuity can be 0 Om and 10 Om and 50 Om, so it’s built into the multimeter that it beeps in this resistance range, and it’s not clear that these mosfets have two legs shorted for all of them. This could be a +20V bus that powers different modules, dc/dc converters...

[harp]

i tested the resistance and it is 10.4ohms. It is marked as x10

It is 01X... letter is always on last place for EIA-96 marking

[grimreaper420]

So this is capacitor C907 in short?

ive tried to draw the continuity lines, at point A, there is continuity everywhere with that side of the fuse. on the other end where the white line just 'ends' there is pretty much continuity on nearly everywhere on that side of the board so i stopped drawing the line

[grimreaper420]

So this is capacitor C907 in short?

yes sir. 10ohms and beeps in continuity mode.

i did a continuity check of 'B' side of the blown fuse and it beeps when i touch either side of C907. Are we getting close?

[lotas]

So this is capacitor C907 in short?

[grimreaper420]

No, they are not paralleled, they only sit on the ground with only one terminal, but the resistor (10 Ohm) seems to have burned out (check), its burnout point is visible.

ive got a really good idea, i will use the continuity and trace the path from the fuses and after the fuses and mark them down on the board. should be easier for us to understand what is coming to the fuse and leaving the fuse

[grimreaper420]

No, they are not paralleled, they only sit on the ground with only one terminal, but the resistor (10 Ohm) seems to have burned out (check), its burnout point is visible.

Ah okay. I think that is just the picture. i tested the resistance and it is 10.4ohms. It is marked as x10

[lotas]

No, they are not paralleled, they only sit on the ground with only one terminal, but the resistor (10 Ohm) seems to have burned out (check), its burnout point is visible.

[grimreaper420]

The resistor next to it is hard to see, are they paralleled together?

I believe so. Attached a better picture

[lotas]

The resistor next to it is hard to see, are they paralleled together?

[grimreaper420]

I forgot to ask, did you ever measure the resistance at these points, did you de-energize the board or was it energized?

i found a short in capacitor (circled), its not close to the fuses though. I dont have thermal camera or lab power supply.

when i measured resistance the board was unplugged. i only tested the voltage with the board plugged in.

[lotas]

I forgot to ask, did you ever measure the resistance at these points, did you de-energize the board or was it energized?

[lotas]

Here it's not clear where A comes from
low resistance between ground if mosfets 2 pcs. and 2 capacitors do not have a short one and this section no longer goes anywhere?

[lotas]

I already wrote that the mosfet should not have a short circuit between the legs...
Do you have a laboratory power supply and a thermal imager to determine the heating location?

[grimreaper420]

Here the board is multi-layered, there may be 3 or 4 layers and it’s hard to determine which tracks go where...

i tested the 2 mosfets when the power was plugged in. both of the drains had 19v, the gate on both of them were 9v. does that give any clues?

[grimreaper420]

Here the board is multi-layered, there may be 3 or 4 layers and it’s hard to determine which tracks go where...

I'm not sure I'm testing the mosfet correctly. do you know the best way to test it?

[lotas]

Here the board is multi-layered, there may be 3 or 4 layers and it’s hard to determine which tracks go where...

[grimreaper420]

It's strange, maybe at that time they measured it and there was poor contact between the probes and the contacts, the fuses seemed to have blown?

this is the other side of the board. the red circle highlights the area of where the blown fuses are

[grimreaper420]

It's strange, maybe at that time they measured it and there was poor contact between the probes and the contacts, the fuses seemed to have blown?

Maybe, i usually check a few times before i write my numbers down. The fuse is definitely blown, in continuity mode there is no beep and OL on both of them. i checked with another fuse further up the board and that one beeps.