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820-00165 Missing PM_SLP_S4_L

Z

ZAKLINTOWN

New member
Hi everybody,
Well I have 2 identical MB Air boards(820-00165) both came in with no power/dead - no liquid damage or worked on before, clean boards,
Checked out all the rails, missing PP5V_S4RS3, traced back by EN signals and missing PM_SLP_S4_L
Also checked:
PPVRTC_G3H
RTC_RESET_L
PCH_SRTCRST_L
PCH_INTVRMEN_L
PCH_DSWVRMEN_L
SYSCLK_CLK32K_RTCX1
PP3V3_S5
PM_DSW_PWRGD
PP3V3_SUS
PM_BATLOW_L
PM_RSMRST_L
PM_PWRBTN_L
All present, only one couldn't measure as no oscilloscope SYSCLK_CLK32K_RTCX1(but multimeter picked 0.4 presume it's present), checked U1900/50 all good, double checked pads(corrosion) for R8141 and R7500, all good, Bios chip good with all resistors around it,
Could anybody please give me any hints is there anything else I can check or these are done???
Didn't work yet on these so basically untouched and would like more ideas before applying some heat!
will highly appreciate any suggestions...
 
2informaticos

2informaticos

Administrator
Staff member
Try first to start in SMC bypass.

For the future, post exact measured voltage.
We don't know if PPBUS_G3H is correct now.
Also you forgot one RTC signal, PCH_INTRUDER_L.

Trigger SMC_ONOFF_L and check if PM_PWRBTN_L reacts (drop pulse); use R5115/16 pads, instead of power button.
 
Z

ZAKLINTOWN

New member
Thanks very much,
I?ll try your suggestion as well as value of the PCH_INTRUDER_L
Will reply as soon as it?s checked!
 
Z

ZAKLINTOWN

New member
Well I checked that and didn?t get anywhere, lastly I tried Ultrasonic cleaner, got a fan spin but nothing else, by connecting/disconnecting Magsafe got Mac to boot into login screen, but once switched off same again, only with 4th 5th attempt boots os, SMC??
 
Z

ZAKLINTOWN

New member
Sorry for the silly one, how do I bypass SMC on, by shorting startup pads with tweezers and plugging in Magsafe at the same time?? I?ve nothin else connected to the board apart from display and SSD...
Cheers
 
Z

ZAKLINTOWN

New member
Well I had a feeling that it needs SMC reset after US cleaner, put everything back in and did SMC and Pram reset, working since, have to mention that either SMC or Pram didn?t do anything before UC was done,
So this one is sorted, will leave for testing during the weekend before returning to customer!
thanks very much 2informaticos for getting involved!
 
2informaticos

2informaticos

Administrator
Staff member
Once charger and battery are both removed, that is SMC reset equivalent...
PRAM reset solved your problem.
SMC reset needs to be done only when machine is closed and cannot remove the battery.
 
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