820-3462 sleepless

HI there,
I have 820-3462 that doesn't really sleep.

It responds to the LID being shut by disabling backlight, but the board is still in an ?S0 state, all S0 rails are still there including Vcore.
Has anyone ever had that? what could cause this?
 

2informaticos

Administrator
Staff member
SMC_LID really goes to 0V?
Check what happens with PM_SLP_S3_L at same time.

BTW, any history available?
 
yes, sms_lid goes completely to. 0.001V
PM_SLP_S3_L stays at 3.34V

no liquid damage visible under scope, no evidence of drop damage to the casing

also, results don't change when booted off of known good USB osx
 
Resetting PRAM 3 times has not made a difference.
And yes, USB activity when lid is closed, I have a USB drive with LED that shows it is being read.
 

2informaticos

Administrator
Staff member
If backlight goes off, means SMC informs PCH about lid state.
This could be PCH issue, but try full known good working BIOS, just for test.
 

dukefawks

Administrator
First thing suspect is a software issue. Remove SSD and boot from known good USB drive.
After that disconnect all devices, including keyboard/trackpad/LCD etc. Yes fans will run at full will be slow, but see if it sleeps then.
Any other history? Liquid? Especially SMC area.
 
hey Duke, alles goed?

it's good you reminded me about disconnecting devices. i tried a new flex cable after that, just because one is laying around here on the desk.
Jesus Christ, that was the cause?
It's now sleeping normally...
Thanks 2infos for all fast replies and thanks Duke for your common sense
 
Top