I'm working on 820-3115 board which as customer claims stopped working suddenly. I've inspected it very closely, there is no physical or liquid damage. With battery disconnected and only charger connected it has green light, but it doesn't switch to orange. With battery connected it shows green then orange. Board turns on, there is fan spin. When trackpad is disconnected fan goes to high speed. With trackpad connected it spins with normal speed, though there is no chime, no image on screen. With RAM removed it doesn't beep three times as it should.
Below I post some basic voltages:
PPBUS_G3H - 12,6v
PP3V42_G3H - 3,47v
SMC_PM_G2_EN - 3,47v
SMC_RESET_L - 3,44v
CPU VCORE - 1,12v
PP1V8_S0 - 1,81v
T29BST_BOOST - 2,6v -> isn't it too low? According to schematic it should be 8-12v
What I have done so far:
- replaced clock chip U2600 - no result
- reflowed SMC - no result
- tried new BIOS and new BIOS chip - no result
In another thread Louis wrote, that it can be corrosion under SMC/PCH. There are no signs of liquid on both. I don't know if it's worth to take off SMC and reball it ot it's not this case?
Below I post some basic voltages:
PPBUS_G3H - 12,6v
PP3V42_G3H - 3,47v
SMC_PM_G2_EN - 3,47v
SMC_RESET_L - 3,44v
CPU VCORE - 1,12v
PP1V8_S0 - 1,81v
T29BST_BOOST - 2,6v -> isn't it too low? According to schematic it should be 8-12v
What I have done so far:
- replaced clock chip U2600 - no result
- reflowed SMC - no result
- tried new BIOS and new BIOS chip - no result
In another thread Louis wrote, that it can be corrosion under SMC/PCH. There are no signs of liquid on both. I don't know if it's worth to take off SMC and reball it ot it's not this case?
