820-00165 - fan spins but mac does not turn on

Palhano

Member
This mac arrived without calling, with oxidation on the U3540. I changed component and reballing in SMC. Mac worked for two months and now the card turns on, fan turns on, stops and turns on again. But not working.

RTC_RESET_L - 3.26V
*PCH_INTRUDER_L - 1.65v (change resistor for 100k?)
PCH_INTVRMEN - 2.5v
PCH_SRTCRST_L - 3.26V

PPBUS_G3H - 8,6
PP3V42_G3H - 3.4v
PPVRTC_G3H - 3,3V
PP5V_S5 - 5v
PP3V3_S5 - 3.3V
PP3V3_SUS - 3.3V
SMC_ONOFF_L - 3,37v


SMC_ADAPTER_EN - 3.3V
SMC_PM_G2_EN - 3.4V
PM_BATLOW_L - 3.3V
PM_PWRBTN_L - 3.4V
*PM_RSMRST_L - 3V (Board turns off when I check)
PLT_RESET_L - 3.3V
ALL_SYS_PWRGD - 3.3v
 

2informaticos

Administrator
Staff member
Because of corrosion, may have accumulated crap under PCH area.
Start heating CPU/PCH with good flux; no need to melt the balls!
 

Palhano

Member
I put the logic board in the ultrasonic cleaner and it started working again. I will test it now!
 
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