Camera controller over-heat (no chime)

[DavutAmana]

Hello,

Today I am on an A1466 model 820-00165 motherboard.

All voltage and resistance measurements look good.

I noticed C4002 and C4003 ripped off, so I replaced.

The fan is running but the card does not read USB, no LCD backlight.

With thermal camera I noticed U3900 heats abnormally 46 ° C

On a 35 ° C functional card

PP1V35_CAM is 1.35V

No other physical damage except these 2 torn components.

What do you recommend ?

Thanks in advance.

 

[2informaticos]

Any history fault available?
Who and how ripped off the components; maybe more damage caused on the board.

PLT_RESET_L comes high?
Try known good working BIOS.

 

[DavutAmana]

I am only repairing the board, in general they are poorly stored and have components torn off. ?‍
This is very normal on the cards I make...

Indeed PLT_RESET_L is not present (0V)

BIOS replacement does not change. The problem persists

 

[2informaticos]

Check voltage at pins 7 & 3 of U1950?
Do you get 1.8V at VCORE?

 

[DavutAmana]

PIN 7 = 3.17 V
PIN 3 = 0.17V

I had bad resistance on
SYS_PWROK_R
so I replaced U1950 and R1962

Now i get

PIN 7 = 3.4 V
PIN 3 = 3.4V
PLT_RESET_L = 3.33V

But still The fan is running but the board does not read USB, no LCD backlight.

 

[DavutAmana]

And yes i have
PPVCC_S0_CPU 1,8V

Thanks very much for your help

 

[2informaticos]

Try known good working BIOS.

 

[DavutAmana]

Now I have replaced U6100 3 times, I even rechecked afterwards, all BIOS works on another identical board (1.8ghz 8gb)

The voltages and the diode resistors are also good when I compare with the functional board.

 

[2informaticos]

Can be a simple missing resistor, or bad CPU...

 

[DavutAmana]

I noticed Q1920 with the oxidized and bad pin 1, I replaced the component and did the retrofit.

Do you have any advice on resistance checked?