A1707 - 820-00281-A Missing S4


New member
Happy Thanksgiving!

I bought an A1707 that was liquid damaged. It sometimes turns on after leaving it alone for a while (albeit doesn't boot, but that might be a separate problem).

Right now, these are what I probed for (not in order). It shows 0.05A and 20V from the USB-C meter. I poured Alcohol on the board and it doesn't get that hot anywhere.
  • PPBUS_G3H - 12.62V
  • PP3V3_S5 - 3.327V
  • SMC_PM_G2_EN - 3.42V
  • PP3V3_G3H - 3.42V
  • PP3V3_S4 - 0V
  • PP5V_S5 - 5.15V
  • PPBUS_HS_OTH3V3 - 12.62V
  • P5VS0_TG - 0V
  • P5VS0_VBST_R - 4.79V
  • P5VS4_SW - 0V
  • PM_EN_PVXS5 - 3.4V
  • P5VS5_PGOOD - 0V
  • PM_SLP_SUS_L - 0V
  • S5_PWRGD - 0V 100Ohm to ground right after powering off but rises to 90k
  • P5VS4_PGOOD - 0V
  • PP3V3_S5 - 5V
  • P3V3S5_SW - 3.3V
  • PM_EN_PVXS5 - 3.42V
  • P3V3S5_EN_RCD - 3.3V
  • P3V3S5_COMP2 - 1.96V

I think the main problem is that S5_PWRGD is missing even though P3V3S5_EN_RCD, PM_EN_PVXS5, and PPBUS_HS_OTH3V3 is present. Does this mean I have to change U7650? I don't see any damage near there. I don't have an ultrasonic cleaner so would prefer to root-cause it before purchasing one.

Thank you!


New member
So somehow I now have S5_PWRGD but I don't have P5VS4_PGOOD, and R7802 is approximately 100K.

I then found that P5VS4_EN_RCD is missing , and more importantly that PM_SLP_S5_L (its dependency) is missing.

Could you please point me what PCH signals need to be present for PM_SLP_S5_L to be alive? I see some articles online but they're for older gen CPUs. This is a 7th gen Intel - I have no idea how SLP_S5_L is released.

Sanity check:
- PP5V_S5 - 5.00V
- PP5V_S4 - 0.00V

Pins around U7650:
- P5VS4_DRVL (DRVL1 pin) - 0V
- P5VS4_DRVH (DRVH1 pin) - 0V
- S5_PWRGD (PGOOD2 pin) - 3.28V
- P5VS4_PGOOD (PGOOD1 pin) - 0V
- P5VS4_EN_RCD (EN1 pin) - 0V
- PM_EN_PVXS5 (EN pin) - 3.417V
- P5VP3V3_VREG3 (VREG3 pin) - 3.3V
- P5VP3V3_VREF2 (VREF2 pin) - 2.00V

Figuring out why P5VS4_EN_RCD is dead:
- PM_SLP_S5_L - 0V
- PM_SLP_SUS_L - 3.32V

Going through some related PCH voltages:
- PP3V0_G3H (checked for stability) - 3.08V
- RTC_RESET_L - 3.078V
- PM_PCH_PWROK (I think this won't come until S0?) - 0V
- PM_BATLOW_L - 3.31V
- PM_PWRBTN_L - 3.3V
- PM_SYSRST_L - 3.3V
- PCH_INTRUDER_L - 2.78V (Seems lower?)

Thanks again, I appreciate the help.
Last edited:


Staff member
Check PM_RSMRST_L and PM_PWRBTN_L signals.
Trigger SMC_ONOFF_L and check for drop pulse at PM_PWRBTN_L (at same time).
Use SW5200, or R5226 pads, instead of power button.


New member
- PM_RMRST_L - 3.32V
- PM_PWRBTN_L - 3.32V

When I short SMC_ONOFF_L to ground at SW5200, PM_PWRBTN_L (measured at R1802) goes to a few millivolts while I hold the short. It then comes back to 3.3V when I release the short.