ALB-Repairs
Member
Hi
Im usually pretty good with these issues. This one has caught me out. It has no signs of liquid damage.
Its not the typical quarter fan spin issue that relates to PCH/EEPROM/Clock Gen
This is a little different, it seems to be related to SMC support circuitary.
the green light disappears frequently.
PPBUS G3H bounces between 12v0 and 12v6 dependent on weather the fans spinning.
probing Y5010 can cause symptoms to change, anywhere from fast fan no v-core to being in a full S5 state, again, this seems completely random.
SMC_RESET_L present and stable
R4999 good
PP3v42 is stable
R7021 and R7022 current sensing correct
R7051 and R7052 current sensing correct
SMC_BC_ACOK correct, green light present, sometimes loses communication with the SMC, and light goes out.
Checked board with another EEPROM/Bios chip, no change in symptoms.
Fitted replacement SMC. No change in symptoms.
SMC_ONOFF_L is present and stable.
When ive managed to get it stuck in an S3 state i checked the main power rails and found everything present and correct.
I replaced Y5010. C5010 and C5011 with no change in symtoms
any ideas?
Im usually pretty good with these issues. This one has caught me out. It has no signs of liquid damage.
Its not the typical quarter fan spin issue that relates to PCH/EEPROM/Clock Gen
This is a little different, it seems to be related to SMC support circuitary.
the green light disappears frequently.
PPBUS G3H bounces between 12v0 and 12v6 dependent on weather the fans spinning.
probing Y5010 can cause symptoms to change, anywhere from fast fan no v-core to being in a full S5 state, again, this seems completely random.
SMC_RESET_L present and stable
R4999 good
PP3v42 is stable
R7021 and R7022 current sensing correct
R7051 and R7052 current sensing correct
SMC_BC_ACOK correct, green light present, sometimes loses communication with the SMC, and light goes out.
Checked board with another EEPROM/Bios chip, no change in symptoms.
Fitted replacement SMC. No change in symptoms.
SMC_ONOFF_L is present and stable.
When ive managed to get it stuck in an S3 state i checked the main power rails and found everything present and correct.
I replaced Y5010. C5010 and C5011 with no change in symtoms
any ideas?