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I have an 820-00840 on bench which came with water damage. The only area which had slight corrosion was U8210 and R1355. After cleaning and refreshing this area board starts, takes 20V, trackpad clicks but board is stuck at 0,26A. There is no chime, no image, no post. The voltages I have...

I logged in to the system, let all files load and after reboot everything works fine, even sleep mode. @2informaticos thank you for your assistance!

SMC_LID_LEFT/RIGHT are ~1,8v when lid is open and 0,02v when closed. the rest voltages (lid open/closed) LID_OPEN_LEFT ~1,5v / 0,03v LID_OPEN_RIGHT ~1,5v / 0,03v IPD_LID_OPEN ~1,8v / 0,00v R4800/R4801 are measuring 1M, R4804/R4805 are 10K. All are getting 1,8v from PP1V8_SLPS2R. I have...

All mentioned voltages are present. As it turned out there was PPBUS_G3H_TPAD_FLT missing - bad F6700... I don't know how I have missed it, I was measuring the connector in diode mide... After replacing it, haptic is working now, but you pointed another problem, that I haven't noticed before...

I got water damaged A1932 ( 820-01521 board). Motherboard itself had only few small spots of liquid around L7670 and J6620, the rest literally looks perfect. I found out that the battery is dead and needs to be replaced along with trackpad and trackpad flex, which were corroded. I put new parts...

@2informaticos, thank you for info. I’m not going to get involved into such solutions for now, computer gets back to the customer. From one side it’s pity, that Apple has moved BIOS into T2, but from another side - previous “security” of EFI was funny… any person with cheapest programmer could...

Recently I got this machine for EFI unlock. It has T2 chip onboard. So I read about EFI unlock for these devices and got a bit confused. There is misinformation in this topic. Some people think, that it’s possible to read T2 ROM chip and remove EFI password like on machines without T2. Some...

C9501/02 are not shorted. Pin 2 on both caps reads OL, pin 1 reads 0,335V in diode mode. Traces are OK too. data lines diode mode readings (I/O board disconnected): USB3_EXTB_R2D_N - OL USB3_EXTB_R2D_P - OL USB3_EXTB_R2R_N - 0,323 USB3_EXTB_R2R_P - 0,323 USB_EXTB_N - 0,367 USB_EXTB_P - 0,369...

On the similar machine right port works normally, it detects and charges iPhone (or other phones). USB_EXTB_OC_L line is stable 3,3V and doesn't change if I connect USB device.

It raises to 3,3V when computer turns on and stays like that all the time, no matter if I connect devices to USB port.

This one is really strange. I got A1398 which is working perfectly fine except right side USB port, which is working partially - it recognises external flash drives, USB mouses or even boots and works from external drive OS, but the problem is, that it doesn't recognise iPhone at all. AMP meter...

@2informaticos, I have heated CPU with flux and later put board in USC, sadly it hasn't changed anything...

Yes, PLT_RESET_L pulses twice to 3,3v then drops to 0v and stays like that.

I'm working on 820-00165 board, which came to me completely dead. After inspection I found out: - small corrosion between C7400 /C7425 and C2951/C2952 - PP3V3_S4 was completely shorted to ground, but it was caused by damaged U8000 (no corrosion around). I've replaced caps and U8000. Now...

Yes, I know that. Just thought, that my multimeter is too slow to catch short pulse on this line and bad bios cause PCH to cut it off.

For me it sounds a bit strange, that it could kill PCH.. Is it worth to try changing bios? Or in this state it's pointless?

These are reading for lines you mentioned: PM_DSW_PWRGD is 3,42V PCH_DSWVRMEN is 3,22V SMC_ADAPTER_EN is 3,42V PM_BATLOW_L is 3,22V RTC signals: PCH_CLK32K_RTCX is 0,441V PCH_INTRUDER_L is 2,35V PCH_INTVRMEN is 3,22V PCH_SRTCRST_L is 3,3V RTC_RESET_L is 3,3V

I'm working on 820-00165 board, which came to me with description: "Turned off by itself, after a while turned on, but SSD wasn't detected. Now has no reaction for charger". My observations: - board is clean, no corrosion, no water damage, no mechanical damage. - there is no green light when...

I'm sure about these readings. I have injected safe 2V 2 Amps and foud out, that C6455 on PPBUS_G3H_SPKRAMP_LEFT line is glowing on thermal cam like crazy. After removing it PPBUS_G3H and PPBUS_HS_CPU are measuring 0,384V in diode mode, so I think case is solved.