Trigger SMC_ONOFF_L and check for reaction at PM_RSMRST_L and PM_PWRBTN_L.
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820-00928 stuck on 5v
- Thread starter tcampbell34
- Start date
tcampbell34
Member
Both PM_RSMRST_L and PM_PWRBTN_L are 0v. Then when I trigger SMC_ONOFF_L, PM_RSMRST_L has no reaction, but PM_PWRBTN_L goes up to 3.3v for about 3-5 seconds and then drops to 0v again.
3V3_SUS appears at same time?
If yes, check R7810.
If yes, check R7810.
tcampbell34
Member
No 3V3_SUS does not go high at the same time
No pulse at PM_SLP_SUS_L?
Then is PCH problem.
Then is PCH problem.
tcampbell34
Member
Ok I started working on this again. I checked and was not getting any pulse on PM_SLP_SUS_L, but I had my doubts it was a PCH issue. I removed U7000 again and checked diode mode values on all the pads and compared them to a good board. I noticed pad 6 and 31 were higher than normal. I replaced Q7030 and Q7040, and the diode mode values now match my good board, but still only get 5v on the charger. I connected the battery again and still have 20v 0 amp draw. Checked for a pulse at PM_SLP_SUS_L again and this time it does go to 3.3v and stays like that. PM_RSMRST_L also goes high and I noticed the CPU was getting warm, as if the board was turning on, and CPUVCORE voltage was preset at .6v. I put the board back in the case and connected everything and when you open the lid, nothing happens, but if I hit the power button, it actually turns on and boots. Left fan is spinning at high speed, but right fan is normal. Diagnostic mode reports there may be an issue with the fan, but nothing else. If I connect the charger, it does not charge or recognize the charger on any port. I also noticed that USB devices are not recognized at all either when connected to any of the ports. The light on the USB does not even turn on.
tcampbell34
Member
I fixed the left fan issue. Q6000 was ripped off the board and pad 2 was gone. I ran a jumper and replaced the chip and now both fans run normal. Also it does turn on when you open the lid or press the power button. Still have issues with USB ports and charging. I noticed SMC_USBC_INT_L is 0v and R3038 is good.
Do you get 5V at L3500, or LB700?
Depending where the USB device is connected.
Depending where the USB device is connected.
tcampbell34
Member
I do not get 5v on either coil
So USB devices are not recognized.
Just in case, check for short at both coils.
Just in case, check for short at both coils.
tcampbell34
Member
I figured it out. SMC_USBC_INT_L need to be high and it was 0v. Looking over the points on the board that signal goes too, I noticed a small amount of corrosion on the pads for JB200. I cleaned the pads with new solder and now SMC_USBC_INT_L is 3.3v and the board turns on using just the charger. I guess the corrosion there was shorting that signal somehow, even though it did not show a short. USB devices now works also on all 4 ports also. Thanks for the help.
Thanks for feedback.
It will help other members for sure.
It will help other members for sure.
Please, open new thread with your problem.
Same symptom, doesn't imply to have the same culprit/solution.
Same symptom, doesn't imply to have the same culprit/solution.