820-2879-B green light but not turn on

Dewanbd

Member
Hi,
Unit has minor water damaged, green light but not turn on
smc bypass it turn on and
PPVCORE_S0_CPU=0v
PP5V_S0=0v
PP3V3_S0=0v

PP3V42=3.4v
SMC_BC_ACOK at 3v on pins 1/2= 3.2v
PP5V_S5=4.9v
SMC_PM_G2_EN=3.42
Any help please.
 

2informaticos

Administrator
Staff member
Some voltages don't have S3/0 in the name, but you should know which sleep state are related to.
VCORE???
 

2informaticos

Administrator
Staff member
So your board turns on, but not working; is a difference.
Board tries to turn on in normal mode at least?
Check for pulse at big coils.

Do you note any variation on VCORE in the first 10-15s?
PCIE_RESET_L goes high?

Did you try known good BIOS?

Post exact ohm resistance to ground at L6995; should be higher than 30K.
 

Dewanbd

Member
All big coils= .99 to 12V.
variation on VCORE in the first 10-15s, 1.1V to drop 0.99V
PCIE_RESET_L=3.2V stable.
not tried good bios.
exact ohm resistance to ground at L6995= 2M
 

2informaticos

Administrator
Staff member
"Board tries to turn on in normal mode at least?"
???

Do you get USB activity, when board turns on?
 

Dewanbd

Member
Know good bios no luck.
how do i know that it tries to turn on in normal mode? It turn on only bypass SMC. Yes, USB activity.
 

2informaticos

Administrator
Staff member
"how do i know that it tries to turn on in normal mode?"
Any pulse at PM_SLP_Sx_L signals, when trigger SMC_ONOFF_L?

BTW, this board doesn't turn on by itself, like iCore boards; need to press power button.
 

Dewanbd

Member
BTW, this board doesn't turn on by itself, like iCore boards; , You are absolutely right, KB issue, Solve by changed KB. Thanks.
 
Top