820-3209-a died when played game

[ert]

Hello there.
Computer turned off while playing a game (roblox - for the full picture). No previous problems, water marks or other repairs. Perfect condition.
The board on the table reaches 14.92V and .23A, the light turns green and then orange, the fan slowly spins up to medium higher speeds. Everything seems normal.
PPBUS_G3H reaches .133 (diode mode, red to ground) and 8.39V when powered.
L7550 drops slowly 2.3 to 1.3ohm (normal orientation: black to ground) and L7510 stable 2.3ohm.
What is wrong, help please.

 

[2informaticos]

Do you get voltage on all coils?
PLT_RESET_L comes high?

 

[ert]

Hello,
voltage on all coils (exl. L7550 & L7510). No V on plt_reset_l (power on sequence is incompleted?)

 

[ert]

Btw, diode mode on plt_reset_l .400 (red to ground).

 

[2informaticos]

ALL_SYS_PWRGD comes high?

 

[ert]

ALL_SYS_PWRGD 3.3V

 

[2informaticos]

Check U7400 voltages: pins 15, 24, 40, 1, 2.
Be sure R7402 is good, also its traces/solders.

 

[ert]

U7400:
1: 3.34v / .380(1-red to gr)
2: .35v(1) and 8.39v (2), r7402 91kohm
diode mode: .620(1) and .132(2) red to gr.
15/24: 5v / .380
40: 4.95v /
Everything here looks good.

 

[2informaticos]

Try known good BIOS...

 

[ert]

Have you got a proper one, could you check it, please?

 

[2informaticos]

820-3209-a clean fixed ssn.rar

drive.google.com

Just for test, not sure if really good...