820-3332 Green light no start

[JohnB8812]

Yeah I was going to say probably a sensor issue or a bad SMC.

 

[rlowe215]

CHGR_AMON 12.6v
CHGR_BMON 0.05v

 

[2informaticos]

"CHGR_AMON 12.6v"
This is really bad and there is your problem.
Check R7021/22.

 

[rlowe215]

sorry my bad correct measurement are
CHGR_AMON 0.004v

And one more bad thing is that what I first was start with smc bypass wasnt start =( its just fanspin cykling for about 10sec over and over again. Put it all together and with battery connected its fan spin but its like the fans pulsing.

 

[JohnB8812]

That sounds like maybe a current sensing issue. Resistance between pins 17/18 and 27/28 of the ISL6259?

 

[2informaticos]

In some way, you had an working board before SMC replacement.
MLB doesn't boot at all now.
I suppose bad/incorrect SMC, or bad solders.
Did you take it from donor board, same model?
Reball original SMC and try it again.

 

[rlowe215]

working I dont know but with the keyboard it started up but not boot in to system. without the bad keyboard it didnt start before. and yes the smc are from same modell but try to do it all over again with old smc

 

[rlowe215]

ok, tried another smc and now im back where we started accept ppbus is 12.6 so only progress. Starts upp in smc bypass mode but dont find ssd. no green light

if tryin to start normal nothing happens, get green then orange light, no fan spin

it using 0.148 Amp if its any help.

 

[2informaticos]

0.148A when board off, without battery?
Have to find the overcurrent.

 

[rlowe215]

0.148 without battery when I plug it in and nothing happens so guess not powered off.

 

[2informaticos]

Post resistance to ground on 3V42 power rail, ohm mode and diode mode too (red probe to ground).

Post SMC_DCIN_VSENSE, SMC_DCIN_ISENSE and SMC_CHGR_BMON_ISENSE.
Also check AVREF_SMC voltage.

 

[rlowe215]

3V42 0.305V . 2.8 kohm
SMC_DCIN_VSENSE . 0V . 0.683V . 5.34 kohm
SMC_DCIN_ISENSE . 0.004V . 0.705V 7.86 Million ohm?
SMC_CHGR_BMON_ISENSE 0.007V . 0.709V . 7.91 Million ohm

AVREF_SMC 3.29V

 

[2informaticos]

"SMC_DCIN_VSENSE . 0V"
You should get 2.7V aprox; check Q5310 area.

 

[rlowe215]

q5310
DCINVSENS_EN 0V


PM_SUS_EN 0v

 

[2informaticos]

Check PM_SLP_SUS_L and SMC_BATLOW_L.
If Ok, then check U7940 area.

 

[rlowe215]

PM_SLP_SUS_L 3.3v
SMC_BATLOW_L as before 0V
PM_BATLOW_L 0V

 

[2informaticos]

Do you have original 85W charger?

 

[rlowe215]

yes i test with bouth original charger and my psu

 

[rlowe215]

changed Q7842 and got PM_SUS_EN but seems it blows again all the time

 

[2informaticos]

Try to start in normal mode with both charger and battery connected.