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ok... where is this voltage dividers then? where should I be measuring? If i measure at the solder pad of the missing U7740, I get nothing... diode mode to ground is just 1....

I can only see: " 1.05V S5 LDO Ibex Peak-M requires JTAG pull-ups to be powered at 1.05V in S5. Pull-ups (3) must be 51 ohms to support XDP (not required in production). 70mA is required to support pull-ups. Alternative is strong voltage dividers (200/100) to 3.3V S5, which burns 100mW in all...

i still dont understand, U7740 should be "NO STUFF" and how it comes from 3V3_S5? I checked other 820-2850 board and U7740 is also not presence.. diode mode to ground is 1 (open), other 820-2850 also confirm the same.

I dont have any oscilloscope, but my voltmeter is showing PP1V05_S5 is cycling between +0.005v and -0.004v :rolleyes:

If you means " Misc Power Supplies" and " Power FETs", then I have checked and they all cycling too, except of course PP1V05_S5 because U7740 does not exist. PPBUS_G3H and 3V3_S5 are stable. There is no 3V3_SUS signal on this board. When the board is in the machine, how come it doesnt wait for...

PM_ALL_GPU_PGOOD is cycling... remove RAMs make no difference

i press and maintain power button, then connect charger, NO GREEN LIGHT, then release charger... same thing, fan spin up and down, the different is this time the fan spin higher and louder. Nothing shown on the screen. Symptom same as before changing C9560. No history available, board looks...

PPVCORE_S0_CPU is cycling between 1.1v and 0v. I cant even turn it off, when i press the power off button, it doesnt do anything, all i saw was the fan spin up and down every 3 seconds. Any other way to do SMC bypass mode without the power button?

C9560 replaced. PPBUS_G3H = 12.5v ALL_SYS_PWRGD is cycling between 3.3v and 0v

i am a bit confused as to what you recommend to do, let me clarify: 1) remove R2415 (instead of the L2406) 2) remove 8904/11 (is this a necessary steps, why did you said might need to repeat if left in place) Or just R2415 is sufficient?

i read on the demux site, it said that: "For those with repeated failed flashes. We have determined the cause to be noise on the TCK line. This can be fixed by adding a 100pF capacitor between TCK and ground(GND). If the above fix still isn't working for you, you can temporarily remove L2406...

I removed L2406, fan dont spin and i tried to flash but it keep on failing... and then suddenly fan started to spin high.. now whenver i plug magsafe in, fan will spin slow and then turn to high. Is the fan supposed to spin when I have the L2406 off? Did i mess up something?

i have removed both SMC and U7000, now both pin 10 and pin 11 are high value around 1087

disconnecting webcam didnt change anything. But I measured the Q5502 again and it seems bad. Removed it and HWMonitor still show the same reading. I have replaced it again and the high spin fan is gone!

HWMonitor said: Airport Proximity 129 C Mainboard Proximity 128 C Heatpipe Outgoing Air 128 C

ah.. I just found out that the gmux is probably flashed.. as I did nvram reset and STILL only seeing iGPU. That shouldnt have anything to do with this high fan spin right? Let me try HWMonitor first.. dont have the ASD EFI..

Located R9235 touching the R9237. Corrected it and now system boot up fine. I also saw missing Q5502, I took one from donor board and replaced it. However, I still have high fan spin... where should I look now?

Ok I disabled GPU in the original bios and now I believe the problem is corrupted LVDS data line.

can you educate me what had happend? 1) why a bad Q7080 would cause a green light blink? 2) why using a fake charger would help identify the issue?

Removed Q7330, short is gone. Replaced Q7330, fan started to spin. Confirmed this board is working now. Thanks!