Macbook Pro 820-00850 stuck at apple logo

Sam7771

New member
I am working with a 820-00850. When power up without the battery connected, keep on loading with the apple logo (progress bar filing slowly and checked for about 10 min and turned off by me since fan is working very fast). Fans are working at their maximum speed from the beginning.
It takes 3.1A and voltage is 19.45V according to USB-C meter. Customer said that he spilled some water on it but no marks of water damages. Sometimes, one vertical line also coming at the right side of the screen.

Any directions to fix the problem?
 
This model requires a good battery to be connected or it wont boot and the fans will spin high. Connect a good battery to it and see if it boots
 

2informaticos

Administrator
Staff member
There should be a temp sensor issue.
Liquid spill caused problem with some I2C bus.

Disconnect webcam and try again.

Trackpad/keyboard must be checked too.
 

Sam7771

New member
Even after removing everything and power-up with fans and power connected. We have the same issue. Is it a good idea to reflow U5850, 5860 and 5870? Though no green colour corrosions, I can see corrosions are developing.
 

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2informaticos

Administrator
Staff member
If you remove EVERYTHING, fans will go high, of course.
Some temp sensors are external, like in trackpad board.
 

Sam7771

New member
Yes I removed everything. I reflowed all three chips and no luck. still fans works at maximum. Specially left hand one when look from the side of the battery.
 

2informaticos

Administrator
Staff member
"Yes I removed everything"
I just said that fans go to max in such case.
SMC cannot detect temp sensor in trackpad, for example...
 
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