820-00840-A no power, mac heats up and sometimes coller turns

[iClub]

helo, my friend I'm with this mac that has been in contact with liquid, the machine seems to turn on, but it doesn't show an image. the components D330 and D3300 are missing and it is slightly cracked. The region around U8400 suffered from oxidation, where I had to make a jumper in the ISNS_LCDBKLT_P U8400/c5452 mesh.

Voltage: PPbus_g3h 13.09V; PP3V3_G3H 3.42V; PP5V_S0 5.13v.

 

[2informaticos]

Missing image and backlight at same time?

Did you check for USB activity?

 

[iClub]

I noticed that the ISNS_LCDBKLT_P track didn't have a pad connection to the board, so I performed a jumper from IC U8400 to C5452.

Mac powers the external SSD, but does not start the external ssd. No image on HDMI.

 

[2informaticos]

No reason to search for image/backlight, if you cannot confirm USB activity.
I suppose the board has more corroded points...

 

[iClub]

Not from the image and not even the sound signal that it is connecting, can be the BIOS causing it ?

 

[2informaticos]

Please, use a better translator...

 

[iClub]

Do you think Bios is corrupted, and putting another BIOS file will solve it?

 

[2informaticos]

I can suppose that, but not sure.
If you do not try, will never know...

 

[iClub]

I rewrote BIOS, but it still has the same defect.
In the thermal camera it starts q3100 the component that presents greater heating.

 

[2informaticos]

If you connect charger to the other port, Q3100 is still the hotest?

 

[iClub]

In the first door there is no heating in Q3100, but in the second door yes.

 

[2informaticos]

You still have board areas affected by liquid, maybe even CPU is bad.
You should try first to heat BGA chips with quality flux and pass the board through ultrasonic cleaner at the end.