820-2936 shut off when magsafe unplugged.

[Yoel Ren]

this mac came dead, previously worked on other store,
replace u7000 cause its ugly as f, with blown r7021, r7022, and r7025 out of value, r7001 out of value, all replaced, value good.|
now mac will turn on, see battery, can charge the battery.
but unplugging magsafe will shutdown the mac.
but this mac can run off battery fine.
any idea whats causing this ?

 

[2informaticos]

Is not very clear, how can run with battery alone?
You've said turns off when unplug the charger.
Try a better way to explain actual situation.

Run corresponding ASD...

 

[Yoel Ren]

no no its bizarre i know.
mac will turn on with battery connected, and run off battery.
BUT if I attach charger to it and then rip it out, mac will shut down.

 

[2informaticos]

There must be something else corroded near U7000.
Check R7000 first.
Be sure all traces and solders are good.

 

[Yoel Ren]

so i found out, that mac only behave like this with BIL connected.
if I unplug BIL, its normal.
Using KNOWN good BIL will still behave like that, so the problem is still from logicboard..

 

[Yoel Ren]

r7000 value is normal, 0 ohm.
checked all traces around u7000, all is connected

 

[2informaticos]

Check SMC_LID signal with BIL connected.
Inspect around J6955 for corrosion; pins and caps.

 

[Yoel Ren]

theres 3.4v at smc lid_r whether BIL is connected or disconnected.

 

[2informaticos]

BIL can only affect lid signal, or battery bus.
So test with known good battery.