820-3115 Power only with charger, Unresponsive Power Button

Rubedizzle

New member
Hey there folks,

13" Macbook Pro mid-2012 (non-retina) i5 2.5GHz
820-3115

System will only power on after plugging in the charger, and will turn on automatically. System is completely unresponsive to the Power Button.

When system boots up, it works flawlessly, and can be on/in sleep for days on end and start right back up and work normally. Charger cable can be detached and it will work perfectly. When plugged in, get both green light on the magsafe and orange when charging. If I shut it off, I can't turn it back on unless I disconnect/reconnect the battery, then plug it in the charger.

Battery is showing 'Service Battery', but does charge, and hold a 4hr+ charge. When I first got this system in, the status was 'Replace Soon', and it has been sitting in storage for 5 monthes unused since then.

I believe system had some liquid damage based on the water stains on some pads (pictured), but it was cleaned with isopropyl before ending up in my hands, so unsure about the affected area.


Things I have checked:

R5014 has 3.47V on both pins

SMC_ONOFF_L 3.47V when on, doesn't move when power is pressed, stays at 3.47V. Measured from the few resistors near the keyboard connector.

Noticed there is no R5016 resister, just two pads, and doesn't look like there was solder there before. One side of the R5016 pads is 3.47V, the other 0V.

Don't notice any corrosion around U5010, and it appears to have PP3V42_G3H at 3.47V


Interestingly, if I measure SMC_RESET_L using the probe point above UF5010, I get 3.47V, but the computer shuts off immediately.

Photos attached of the U5010, SMC area, and R5016 area.
 

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Last edited:

Rubedizzle

New member
Hey Duke,

Yes I did, should have mentioned that. Unfortunately same issue :(

Should also mention I read that shorting pin 5 from the right of the keyboard connector to ground will simulate the power button, no luck :(

Is R5016 missing the actual resistor an issue?
 
Last edited:

dukefawks

Administrator
R5016 is the power button pad and nothing is supposed to be there, just a point to power the board on. If you short out the pads does that power on/off the machine?
 

Rubedizzle

New member
R5016 is the power button pad and nothing is supposed to be there, just a point to power the board on. If you short out the pads does that power on/off the machine?

Hey Duke,

Shorting pins of R5016 works for turning the laptop on and shutting it off! A good sign....
 
Last edited:

dukefawks

Administrator
Must be a bad connector then or trace from R5710 to the connector. Short both sides of R5710 to GND and see if you can power on/off the board like that
 

Rubedizzle

New member
Unplugged the keyboard and tried shorting pin 5 of the connector (on the motherboard) to GND, and it indeed boots up. Bad keyboard connector likely then?
 
Last edited:

dukefawks

Administrator
I don't know, you say you tried a known good keyboard....but it sure looks like a bad keyboard or bad connector.
 

Rubedizzle

New member
Yep tried keyboard from another system I have here that I am pretty confident is fine. At this point, hoping I am wrong.

I have ordered a new top case for this system as the current one is pretty beat up and keyboard is included, so will report back then after making the swap.

Thanks Duke
 
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