820-2850 green light cycling at pin1 of F7040 with real charger but stay at 0.1v with fake charger

[protocold]

Removed F7040.

when plug real charger, pin 1 slowly drop from 12.5v and then cycling.

When plug in fake charger, pin 1 dropped from 12.5v to 0.1v and stay there..

.

 

[2informaticos]

Check diode mode to ground at pin 2/F7140.

 

[protocold]

you mean F7040 instead of F7140 right?

If so, both pin 1 and pin 2 diode mode reading is 377 when the fuse is removed.

 

[2informaticos]

Correct, is F7040.

With fuse in place, still cycling PPBUS_G3H?
Check if 3V3_S5 appears at same time.
Check siode mode to ground on all big coils.
Also check if starts in SMC bypass mode.

 

[protocold]

Under normal situation, when the fuse is removed. pin 1 should have stable 12.5v right? [and it is not]

May I ask what is the rationale behind this to put the fuse back instead of looking troubleshooting pin 1? [really trying to learn]

 

[2informaticos]

Some old models fluctuates if 3V3_S5 is not detected.

 

[protocold]

yes sir. with fuse in place, 12.5v is now stable [ i dont think it was stable before].

Fan starts and stop and cycling...

ALL_SYS_PWRGD cycling between 3.3v and 0v.

How to do SMC bypass when the board is removed from the case?

 

[2informaticos]

Solder an wire to a convenient point of SMC_ONOFF_L line.
Then touch any metal plate of the chassis (ground).

 

[protocold]

SMC bypass mode: high speed fan, but still on and off

PPVCORE_S0_CPU is cycling between 1.1v and 0v [diode mode to ground is 063. Known good is 059]
PPVCORE_S0_GFX is cycling between 0.86v and 0v [diode mode to ground is 139. Known good is 067]

 

[2informaticos]

Check for pulse at PM_PCH_PWRGD and PLT_RESET_L.

 

[protocold]

Both PM_PCH_PWRGD and PLT_RESET_L pulse between 3.3v and 0v.

 

[2informaticos]

3V3_S5 is stable?

Just in case, try known good BIOS...

 

[protocold]

PP3V3_S5 is stable at 3.3v

 

[2informaticos]

GPU voltage tries to appear?

 

[protocold]

PP3V3_S0GPU pulses between 3.3v and 0v.
PP1V05_S0GPU pulses between 1.05v and 0v.

PPVCORE_GPU pulses between 0.4v and 0v.

 

[2informaticos]

Check if all output voltages from page 72 try to appear.

Also check if board stays on removing Q7530.

 

[protocold]

page 72:

PP3V3_S3 = 3.5v pulsing
PP1V5_S3RS0 = 1.61v pulsing
PP1V2_S0 = 1.18v pulsing
PP1V8_GPUIFPX = 1.73v pulsing
PP3V3_S0 = 3.3v pulsing
PP3V3_S0GPU = 3.24v pulsing
PP5V_S0 = 5v pusling


PP3V3_S3 and PP1V5_S3RS0 seem to be slightly higher.. is that OK?

 

[2informaticos]

Not big difference.
What about Q7530 removing?

 

[protocold]

same thing if Q7530 is removed. fan spin on and off.

already tried known good bios too.

 

[2informaticos]

Still turns off if remove RAM modules?