820-3437 Problems

tlough75

Member
So I have an 820-3437 board with no green/orange magsafe, but I have PP3V42, PPBUS_G3H is 8.18V and SMC_RESET_L is at 3.3V. There was corrosion on L5001 which resulted in loss of pads, had to run a wire to R5193, R5177 & R5178. Before I repaired traces I powered on board and got fan spin. After I get intermittent light but PPBUS is 8.18V. I checked SDA/SCL and they are at 3.3V. Is the next logical step to go after the SMC? I tried a gentle reflow but that didn't change anything. I'm wondering if I should just reball it.
 

2informaticos

Administrator
Staff member
Check PPBUS_G3H voltage disconnecting LIO flex.
Did you have 8.18V before runing the wire?
Post exact diode mode readings on SCL/SDA lines.

Do you have now high level on all 4 SMC_TXX lines?
I recommend you to reball SMC; because of so close corrosion...
 

tlough75

Member
Yeah I believe it was 8.18V before wires but I do not remember. Going to reball SMC. Already started before I saw your reply. I will post back what happens...
 

tlough75

Member
Ok, so I reballed and replaced the SMC.

SMC_TMS - 3.42V
SMC_TDO - 3.42V
SMC_TDI - 3.42V
SMC_TCK - 3.42V

SDA and SCL lines are at .537 on diode mode. PPBUS is still 8.17 but I now have a green light on the charger.
 

2informaticos

Administrator
Staff member
Machine still doesn't start, nor even in SMC bypass?
You should try another SMC.
Test first disconnecting BIL connector.
 
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