820-00840. After liquid cpu fan on then off

[spackidagoosh]

"Small" water spill on the keyboard. Keyboard flex was destroyed. There was a small spot (picture attached) around C7051 and Q7040. Cleaned around the two components. Replaced the flex cable and the machine boots, charges, and does boot into the OS. Keyboard and touchpad work.

When you first start the computer the CPU fan goes on and off about 10-15 times. If the battery is disconnected I have the fan issue but the computer runs normally.

If the battery is connected it charges, has the same fan issue, but after login the computer shuts off after a minute or so.

Other than just replacing the two components is there a way to test which one is the culprit? I currently do not have a donor board for this model.

 

[2informaticos]

Post exact voltage at F7000, w/ and w/o battery connected?
Also check the resistance over C7020/30.

 

[spackidagoosh]

13.07 without battery
12.58 with battery

C7020 - 2.4
C7030 - 2.4M

 

[2informaticos]

Sorry, check over C7023, instead of C7030...

 

[spackidagoosh]

C7023 2.5

 

[spackidagoosh]

Also... I tried a replacement keyboard/palm assembly and a new CPU fan. It does the same thing. I also located a donor board in my stack.

 

[2informaticos]

You should replace Q7040; check its traces and solders.

 

[spackidagoosh]

Replaced Q7040. The fan does not spin loudly every time. Only the first time on a fresh boot. It stays on while charging now. The fan does not seem to run at all now. If I run apple diagnostic it does the loud fan spin and comes back there may be an issue with the fan Error PPF003.

 

[spackidagoosh]

I have swapped the fan with another but the same results. I guess I could order a new fan but I don't believe that will make a difference.

 

[spackidagoosh]

Resistance
R4800 - 36
R4805 - 46
R4810 - 100

On my donor board, I am getting....
R4800 - 46
R4805 - 46
R4810 - 100

Would the R4800 difference matter?

 

[2informaticos]

Possibly bad fan circuit, placed on the keyboard.

 

[spackidagoosh]

Moving the board to another case reproduces the same issue. SMC issue?

 

[2informaticos]

May have crap under keyboard connector.
You've said was affected by liquid...

 

[spackidagoosh]

That's one connector that I do not want to remove unless I absolutely have to. Although the connector looks fine, there must be a damaged pad underneath, like you said. What would my options be to run a wire? Pins 2 and 3 of the connector are FAN_LT_PWM and FAN_LT_TACH.

 

[2informaticos]

That only helps if no leakage between pins, caused by possibly crap underneath.
Is a chance, try and see...

 

[spackidagoosh]

Logicboard Keyboard Connector....
No pins from the connector are shorted with the ones next to them. I check both sides of the connector for continuity.
PIN 2 of the connector FAN_LT_PWM has continuity to Q4800 pin 3
PIN 3 of the connector FAN_LT_TACH has continuity to R4800 and R4805

I have tried the logicboard in a known good palm rest/keyboard and new cable. I am waiting for a new keyboard connector to come in. Is the anything else that it could be other than the connector?

 

[2informaticos]

You can try the SMC from donor board...