A1990 820-01814-01 no boot

[Roshon]

I have an A1990 820-01814-01 with no boot.

It powers on, I have 19.5V on ampmeter, and it goes to 2.88A with battery, and with out i get 19.6v and it goes to 0.30A then down to 0.A

Already tried revive and restore DFU with no error but no sucess.

It has fan spin, i get 5v from USB activity. no boot

On big coils I get:

LA350 =0.903V 0V WITH out battery on all coils
LA300 = 1.351V
LA650 = 0.902V
LA640 = 0.904V
LA340 = 0.904V
L7231 = 0V
L7330 = 0V
L7221 = 0V
L7211 = 0V
L7420 = 0V
L7410 = 0V
in the photo with the battery on and fan spin the coils and U1200 gets hot

 

[Roshon]

the customer said it just got hot and shut off

 

[2informaticos]

What about L7700/1 ans L8102?

 

[Roshon]

i found a little corrosion around u5850 i cleaned it up and now i get
NOW I GET POWER WITH OUT BATTERY
19.5v and 0.71A with fan spin cpu not getting hot

L8102 =1.02V
L7701 1.2V
L7700
LA300 = 1.350V
LA350 =0.921V
LA650 = 0.903V
LA640 = 0.909V
LA340 = 0.910V
L7231 = 0V
L7330 = 1.22V
L7221 = 0V
L7211 = 0V
L7420 = 0V
L7410 = 0V

 

[2informaticos]

Seems that only CPU core voltage is missing now.

Just in case, try again DFU restore.

 

[Roshon]

I DID IT FINISHED NOW I DON'T HAVE THE VOLTAGES WITHOUT BATTERY

 

[Roshon]

19.6V 0A

 

[Roshon]

WHEN i plug in the charger the only thing that gets hot on the thermal camera is U3900

 

[Roshon]

when i HAD 19.5V 0A i had a short on PPBUS_G3H BUT GOT 12.2V
NOW I HAVE THE 19.5V AND 0.54A

 

[Roshon]

HI

 

[2informaticos]

Possibly bad CPU...

 

[Roshon]

ANYTHING i can do to check for

 

[2informaticos]

Did you test with 87W charger for sure?