820-4924-a No PP5V_S5_LDO

TBFix

Member
Hi Im working on a board that has green light but no PP5V_S5_LDO. Am i correct in thinking u7501 pin 12 ~(P5VS5_EN) needs to be present for PP5V_S5_LDO to be on pin 29.?.
P5VS5_EN seems to be from SMC_PM_G2 presented on R8140 which reads 0v (100ohms), there does not seem to be a short on either side of this resistor (0.524 diode reading).

SMc issue or is my thinking wrong?.

SMC_RESET_L = 3.3v

ppbus_g3h = 12.6v
pp3v43 = 3.4v
ppvrtc_g3h = 3.4v
 
Last edited:

TBFix

Member
Strange thing happened. I reballed the SMC and fitted properly (tripled checked alignment and placement). After that PP5V_S5_LDO returned and current shot up to 300ma. Now there a short on pp3v3s_5 L7560 on pin 1. Also short on L7630 also so I think the PCh/Cpu is bad . Is there a known issue with these boards and CPU/PCh dying? This is the 3rd one of these over the last few weeks with dead Cpu/Pch.
 

TBFix

Member
Is this model particularly known for cpu pch dying? as its the 3rd one if a few weeks same mobo number all with dead cpu/pch
 

TBFix

Member
Not on this latest one , I removed the smc but short still there the other 2 came in with shorts on pch side of L7630
 
Top