[SOLVED]820-3476 pwr, shift, ctr, opt keys dont work

[MaxFix]

Hello there,

I have a machine with refurbished board in for repair with some weird red shit on it (see picture). Everything works except for pwr, shift, ctr, opt keys.
I get 0V on 1, 2, 3 pins of keyboard connector (J4813).
U4850 is also 0.
U4801 VDD is high. Should I replace it?

THanks!

 

[dukefawks]

Non working power button is unusual in combination with the common Shift/control/option problem. Is the keyboard known good? Is there 3V42 on pin 4 of the connector. Do pins 1 2 3 go high when the corresponding key is pressed?

 

[MaxFix]

So I gave it an ultrasonic bath and power button is back on, which is a victory already.
However, the shift/control/option is still not working. pin 4 is 3.42V. pins 1,2,3 are 0V even when pressing the keys.

 

[dukefawks]

That is either a bad keyboard or a bad connector.

 

[MaxFix]

No Title

Could that be a problem?

 

[dukefawks]

Uhm, trace to pin 4 seems very fucked

 

[MaxFix]

No Title

Yep. Put the wire through the hole 4 and its working like a charm. Thanks Duke.