[SOLVED]820-3330 stuck in a loop

arash

New member
Hi guys,
The board stuck in an SMC_RESET loop, keeps on restarting every 2 seconds. Power pads don't work (shutting it down I mean). Had water damage over the U5750, U7000 area. Both were replaced.
Concerning voltage, everything seems to be right and present. A hint anyone?
Thanks
 

arash

New member
SMC_RESET_L stay at 3.0V , SMC chip was also replaced, problem persists. Green light is present
 

arash

New member
Ppbus_g3h=10.6v , pp3v3_s5=3.3v ,
ppvcore_s0_cpu=1.1v , ppvcore_s0_axg=0v , pp1v05_s3_cpu_vccdq=1.5v , pp1v05_s0_cpu_vccpqe=1.05v , pp1v05_s0_cpu=0.8v
 

dukefawks

Administrator
I assume this was measured on battery else PPBUS is way too low.
PP1V05 is of course not correct at 0.8V but makes no sense as pp1v05_s0_cpu_vccpqe is directly connected to it......
 

arash

New member
PPBUS was measured with the charger connected, no battery attached.
My bad, I meant:
ppvcore_s0_cpu=1.1v , ppvcore_s0_axg=0v , pp1v05_s3_cpu_vccdq=1.5v , pp1v05_s0_cpu_vccpqe=1.05v ,PPVCCSA_S0_CPU=0.8V
 

arash

New member
I guess you meant those 2 current sensing circuits, resistors R7020 and R7050 - those are measured at 0 ohm, as they should I think. R7005 is measured at 20 ohm so those look to be alright
 

arash

New member
The resistance between pins 17 and 18 is 0 ohm, also between 27 and 28. R7005 is 20 ohm. Thank you for your replies
 

arash

New member
Thank you. One line from the two was cut and fixed. Now PPBUS measured at 12.7V, the device finally runs.
It is getting into sleep mode randomly and ASD shows only one error with VP0R sensor, which is measured too low
 

dukefawks

Administrator
Probably bad battery indicator or corrosion in the connector pulling SMC_LID low. VP0R is Q5300, so probably corrosion around there.
 

arash

New member
It was the battery indicator flex cable. Now everything is smooth as it should. Appreciate the help guys!
 
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