ASUS B365 motherboard does not power on and does not trigger repair

ASUS b365 mainboard is not powered on and does not trigger, Nanqiao + 1.0V_ A power supply has no voltage. Replace 5VSB conversion tube and start it normally.

ASUS B365 motherboard does not power on and does not trigger repair

Motherboard version number: ASUS prime b365m-a

Fault phenomenon: main board no power on no power on

Maintenance process:

An ASUS prime b365m-a motherboard is used to test the main board no power on, and the South Bridge to ground Diode value is normal is measured. If the CMOS battery is removed, the discharge is still no power on.
Measure 3vsb is normal, IO switch circuit pin bit, refer to nct67933d pin bit 101 pin o_RSMRST#_R. No VCC was found in rsmrsttriode, it is found that +1.0V_A is applied before RSMRST is turned on.

Measuring south bridge +1.0V_A VCC without VCC.

ASUS B365 motherboard does not power on and does not trigger repair

ASUS B365 motherboard does not power on and does not trigger repair Figure 1.

VCC 5VSB of NB671L is not measured. The fault point is the 5VSB_ATX to 5VSB circuit fault. With reference to B150M-K Boardview, it is found that DPWROK and RSMRST are connected, that is, without using SLP_SUS signal, 5VSB VCC will be turned on directly after 3VSB is generated.

ASUS B365 motherboard does not power on and does not trigger repair

ASUS B365 motherboard does not power on and does not trigger repair Figure 2.

Measure 5V of the g pole of 5VSB convert transistor(P-ditch), find the connected triode and remove it, force the g to be extremely low, and force the 5VSB to be turned on.

ASUS B365 motherboard does not power on and does not trigger repair

ASUS B365 motherboard does not power on and does not trigger repair Figure 3.

Measure+1.0v after dismantling _ a VCC is normal.

590;IMG_259

ASUS B365 motherboard does not power on and does not trigger repair Figure 4.

The standby light of the main board is on, and the screen is connected,Normally booting up.

609;IMG_260

ASUS B365 motherboard does not power on and does not trigger repair Figure 5.