820-00430 - 12v line problems

[Palhano]

The board only turns on the first LED. The others don't light up, not even when I try to turn them on.

As there is no schematic for this board, I am a little confused.

I have 12.1v on PP12v_G3H.
FET_EN_P12v_s5 was 15v, replaces the U6970, now I have 11.2v. The U6970 I removed from another board.

any suggestion?

 

[2informaticos]

"FET_EN_P12v_s5 was 15v"
It should be 22V; Vgs=10V required.

If 12V_S5 is stable, try changing 12V_S0 MOSFET.

 

[Palhano]

I'm a bit confused without the correct schematic.

I changed the Mosfet, but I don't know if it's S5 or S0. I'm using the 00034 scheme. The site shows 2 mosfets, the board has only one.

 

[2informaticos]

In the mentioned schematic, Q8450 is 12V_S0 MOSFET.
Q6970 is 12V_S5 MOSFET.

Did you remove CMOS battery?

 

[Palhano]

Yes, I removed the battery.

In the schematic, I found the S0 and S5 mosfets. But on the board, no.
It is very different from the scheme. Where there are two mosfets in the schematic, the board has only one mosfet.

 

[2informaticos]

820-00034 boardview/schematic should help.