820-3437 boots but restarts

[Biggtechman]

Hello, I just got a macbook air 820-3437 in, its like the 3rd in the last 2 months.

no signs of water damage or drops.
Upon inspection u7701 seems to have some suspect looking balls.
just not shiny.

everything else looks good.

I was informed that the night before it startedto play up it had been left on the bed and was running and had a blanket on it.

I have had it running after a smc reset.
I run a program to monitor fan speed and temperature.
it seemed to run hot and it only showed cpu core 2 and cpu core 3.
Cores was running at 70+
I'm no macbook wiz.
I know window base laptops/computers.

anyway it is unstable. As it is doing the resetting again.

could it be a battery ?

 

[Biggtechman]

Is it normal for it not to show all cores in temperature control program ?

my iMac shows all cores.

 

[2informaticos]

Does it turn off, or restart?
Run ASD and see if any error pop out.

 

[Biggtechman]

I cleaned the board, put some good thermopast on and put it back together.
its running and it passed ASD
it was restarting.
stuck in boot loop.
and after a few restarts it would not turn on at all

 

[2informaticos]

Post some voltages for U7100 then.
Do you get correct PPBUS_G3H and 3V42?