820-00164 No Power

Finally getting around to triaging some of the boards I have laying around that won't power up.

I have a 820-00164 board that shows the green to orange on magsafe charger. Not really sure where to start with no power issues. I have the boardview up.

PP3V42_G3H - 3.41
PPBUS_G3H - 8.57
PPVRTC_G3H - 3.32
PP5V_S5 - 5v
R7080 - 16.30 V

Any insight on what to check next would be great. FYI this board saw liquid damage according to the previous owner. Would love to get it working since it's a 2.2 i7 8gb ram. Overall board looks clean.


Thanks
 
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2informaticos

Administrator
Staff member
Post PM_SLP_SUS_L, 3V3_SUS, PM_RSMRST_L.
Trigger SMC_ONOFF_L and check for drop pulse at PM_PWRBTN_L.
 
Well I got the board to power up. PM_SLP_S4_L was 0v which led me to u6100. For whatever reason two resistors near u6100 were missing. All traces are good. Now the issue I'm having is no video. No chime.
 
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2informaticos

Administrator
Staff member
Do you get VCORE?
Check all SPI Bus Series Termination resistors.
Also check U1950 and U6101 for corrosion.
Do you get 3V at U1950, pins 7 & 3?
 
Yes to vcore.
PPVCC_S0_CPU - 1.8V

Yes 3.4v on pin 7 & 3

No corrosion on u1950 and u6101

All spi resistors good
 
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PM_SLP_SVS_L - 3.32V
PP3V3_SUS - 3.32
DM_RSMRST_L - 3.29V

Now when I trigger SMC_ONOFF_L I get 3.41 on PM_PWRBTN_L
 
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Sorry I wrote that wrong. I edited the post. Fan spins anytime I plug MagSafe in. Still having issue of no video, no chime. Using a 45w original Apple charger.
 
Yes I tested each resistor and checked traces. All is good. What's involved in replacing the bios? Doesn't this need to be programmed first?
 

2informaticos

Administrator
Staff member
Usual external programmer requires to remove the chip.
Medusa programmer can do the job onboard, through J6100 connector.
 
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