MP 1,1-5,1 Logic Board 5.1 - how to find visible errors?

[MediaMix]

I have just received a 5.1 2010/2012 Logic Board from England and are about to install it. But - when I look at the board it looks more worn then my old one. I therefore wonder if there are certain things I have to be aware of. The attached picture show a part of the board that looks dirty or discolored. Is this signs of weekness or can I just clean it. If I can - what can I use to clean it.

 

[Macschrauber]

Its oxidation, those pads are unused. Early development boards had all switches soldered on.

Inspect the pins for the cpu board.

Also check the chips inside the „landing zone“ on top of the PCIe GPU power sockets. One can scratch them off or damage them if taking no care when pulling the 6 pin GPU power cables.

To clean the board you can use isopropyl. Take care to ground yourself and the board for avoiding ESD accidents.

 

[MediaMix]

Its oxidation, those pads are unused. Early development boards had all switches soldered on.

Inspect the pins for the cpu board.

Also check the chips inside the „landing zone“ on top of the PCIe GPU power sockets. One can scratch them off or damage them if taking no care when pulling the 6 pin GPU power cables.

To clean the board you can use isopropyl. Take care to ground yourself and the board for avoiding ESD accidents.

 

[MediaMix]

Ok - thanks! But why are only these pads oxidated? Is it because they are not in use or ... ?

 

[Macschrauber]

Ok - thanks! But why are only these pads oxidated? Is it because they are not in use or ... ?

They were not protected by solder resist. Otherwise, they could not be assembled / soldered during the production process.