MacBook Pro 820-2327-A, have green light, charge, have normal voltage, no chime

[crnimrki]

MacBook Pro 820-2327-A, have green light, charge, have normal voltage, no chime. On power on fan spins 5 seconds then stop and again spin and stay spinning.
CPU Warm, DVD Drive not spinning, Mouse on USB Port inactive. No beeps without RAM DIMM-s.
PPBUS_G3H - 12.55V without battery, 11.99 with battery charging
PP3V42_G3H3.39V
PPVCORE_S0_CPU - 0.98
RAM VOLTAGE 1.49

Where to search

[mon2]

PP3V42_G3H 3.39V

This should really be @ 3v42 (stable). Can you measure the resistance to ground of this rail? No power during the resistance check.

Measure the resistance between F7000 (either side is ok) to VCORE. We are checking if there is a CPU high side mosfet leakage. Place the meter probes on F7000 and the VCORE inductor (L7400 / L7401 - either is ok).

[crnimrki]

This should really be @ 3v42 (stable). Can you measure the resistance to ground of this rail? No power during the resistance check.
54 K

Measure the resistance between F7000 (either side is ok) to VCORE. We are checking if there is a CPU high side mosfet leakage. Place the meter probes on F7000 and the VCORE inductor (L7400 / L7401 - either is ok).

710K

[crnimrki]

710K

One update, sleep light is steady on.
How to check if the CPU is working? I read that VCORE_S0_CPU is around 1.2V but that it drops to 0.98V in a short time if the CPU is working.
Could this be due to a faulty BIOS? Would it be worth flashing the BIOS chip? If so, where can I find an image?

[mon2]

I have a few bios dumps in my database and can link them if required.

What is the voltage to ground on each pin of D6905?

Remove all power, measure the resistance across resistor R6905. This resistor should be ~47R.

Review this flowchart and post details if you find a fault:

https://logi.wiki/index.php/G3_to_S3..._and_Broadwell

[crnimrki]

I have a few bios dumps in my database and can link them if required.

What is the voltage to ground on each pin of D6905?

Remove all power, measure the resistance across resistor R6905. This resistor should be ~47R.

Review this flowchart and post details if you find a fault:

https://logi.wiki/index.php/G3_to_S3..._and_Broadwell

D6905:
1 - 16.30 V
2 - 0 V
3 - 0.01 V
4 - 15,61
5 - 15.61

R6905: 49,30 Ohm

[mon2]

All ok.

Measure again this voltage to ground with the power adapter of PP3V42_G3H.

What is the resistance to ground of PP3V42_G3H? No power during this check.

[crnimrki]

All ok.

Measure again this voltage to ground with the power adapter of PP3V42_G3H.

What is the resistance to ground of PP3V42_G3H? No power during this check.

3.39 V and 49,3 kOhm

[crnimrki]

In my opinion everything is OK until the moment when the CPU needs to boot, read EFI and do POST.
Is it a problem if I reflash the SPI chip?
Can you send me an image?