820-3332-A - fast fans

Gurmon

Member
Hi,

I got a odd one here, i cant solve. So hoping someone has seen this before.
This Laptop came in with no image. This was fixed by soldering around U8900 (i think thats the chip). However, once the laptop gets to the login screen the fans start to ramp up to full speed.

I have tried a known good OSX and its still the same.
This unit passes ASD EFI & OS, as well as the VST & MRI.

The odd thing is, when this unit is in diagnostics mode, the fans are perfect.

I'm seriously stuck on this !!!
 

Joesipaq

New member
It sounds like a sensor issue to me. I had a unit pass all the ASD tests, but upon further inspection, I checked each sensor reading in ASD one by one and found 2 sensors out of their normal range. I suggest you check each one and make sure none are tricking you.
 

dukefawks

Administrator
Maybe it really is getting hot and the heat pipe is not conducting heat, check CPU/GPU temps. Make really sure it is not fan control loading with the OS
 

Gurmon

Member
Still not fixed this. Which means its something dead obvious, which i'm failing to see.

I'm thinking this is a bad battery When its plugged in, PPBUS drops to 10.8 - 11.5V. Unplugged we are back to 12.6V. I dont keep batteries for retinas in stock, so have ordered a top case in for testing.

Lets see..........
 

dukefawks

Administrator
The PPBUS will be the charging voltage of the battery so of course it will be lower with battery connected. Did you check the actual CPU/GPU temperatures? Do the fans ramp up when left in the EFI boot menu?
 

Gurmon

Member
Hey Duke,

Fans stay quiet in EFI Boot menu. They only ramp up once OSX gets to login screen. Also with a clean OSX it does the same.
When battery fully charged, PPBUS only gets to 11.5V. Once unplugged its back to 12.6V.

Waiting for ebay battery to test with.....other than that i've no idea.
 
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