820-00165 does not turn on, cooler rotates.

[iClub]

No signs of oxidation.
Voltage: PBUS_g3h 8.59V; pp3v42_g3h 3.42V;PLT_RESET_L 0v; PM_SLP_S4_L 3.36V ; ALL_SYS_PWRGD 3.33V; pp3v3_SUS/S5 3.34V; PP5V_S0 5.13, *Vcore 1.72V, does not fall to 0.82V.

I imagine it is the Me Bios region.

 

[2informaticos]

"Vcore 1.72V, does not fall to 0.82V"
Why do you expect that?
This is not 2936/3115 board...

Do you ger 3V at pin 3 of U1950?
Also check CPU_VCCST_PWRGD and CPU_VR_READY.

 

[iClub]

0V on pin 3 q8150
CPU_VCCST_PWRGD 1.02V; CPU_VR_READY 0v, when I measure this line the cooler stops rotating.

This is not 2936/3115 board...

I thought it was just as logical rsrs.

 

[2informaticos]

"0V on pin 3 q8150"
Please read my post!!!

 

[iClub]

U1950 1.65V, ranging from 3.3V to 0V.

 

[2informaticos]

You should try full known good BIOS; many links on the forum...

 

[iClub]

PLT_RESET_L is low. Shouldn't it be high?

 

[iClub]

Could you please clean the ME region.

backup1.bin

drive.google.com

 

[2informaticos]

You have many links for clean ME BIOS on the forum.
Test first, to see if is BIOS problem...

 

[iClub]

No result with several BIOS here on the forum. Mac spins the cooler, but no video, no USB activity. I've already checked the resistors and Ci's u6100, u1900, u1950 and q8150, but it still has the same defect.

 

[iClub]

the ci of the camera is heating up, is that normal ?

 

[iClub]

Even if there is no oxidation, perform the Reball SMC ?

I would not like to condemn this mac.

 

[2informaticos]

The board stays on now, fan spins continously?

 

[iClub]

As I said before, the cooler spins, with no sound it's turning on and no USB activity.

 

[2informaticos]

Do you get VCORE and PLT_RESET_L?

Check with finger if U3900 really overheats.

 

[iClub]

PLT_RESET_L 0V; VCORE 1.7V;
u3900 with the finger heats up little.

 

[2informaticos]

U3900 should not heat at all.
It doesn't work if PLT_RESET_L is low.
Check diode mode to ground at PLT_RSET_L.
You should test the board removing U3900...

 

[piernov]

Camera IC can warm up a little bit as soon as it receives power, usually irrelevant.