pad sensor tracks - dark colour

hey,

Just popped the lid on my 60 to clean up the pads due to a lack of velocity sensitivity.

The tracks on the sensor sheet are a dark colour in places, especially at the bit where they curl round into the connector. Has anyone come across this before? I assume that the sheet is gone, but is there anything that could cause this "burnt out" appearance.

Ive got a new sensor sheet ready to install, but was interested in two things: salvaging my old sheet rather than installing the new or should this be impossible then making sure that there isnt anything other than general wear and tear that'll darken the sensor tracks.

(on other note the sheet is also "patchy" looking- although not on the sensors themselves, it looks like the patchiness is actually underneath the sheet, in that i cant scratch it off.)

thanks.

mikolo wrote:hey,

Just popped the lid on my 60 to clean up the pads due to a lack of velocity sensitivity.

The tracks on the sensor sheet are a dark colour in places, especially at the bit where they curl round into the connector. Has anyone come across this before? I assume that the sheet is gone, but is there anything that could cause this "burnt out" appearance.

It's nothing more than oxidation of the exposed traces that go into the connector. Sometimes if traces have too much oxidation -- it will increase the resistance and then cause a bad connection.

This is typical of most PCBs that don't have plating over the traces. You can clean the traces with isopropyl alchohol and a q-tip -- or if you're really careful a white pencil eraser -- just make sure not to damage the traces -- they can easily lift off the pcb if there's too much force put on them.

To be on the safe side, make sure you let everything dry before you turn back on your machine.

[quote="mikolo"
Ive got a new sensor sheet ready to install, but was interested in two things: salvaging my old sheet rather than installing the new or should this be impossible then making sure that there isnt anything other than general wear and tear that'll darken the sensor tracks.

(on other note the sheet is also "patchy" looking- although not on the sensors themselves, it looks like the patchiness is actually underneath the sheet, in that i cant scratch it off.)

thanks.[/quote]

The patchiness might be from the old adhesive used to affix the sensors onto the mounting board.

cool thanks- that makes sense, the bit that curls round is the only bit that seems to be exposed. thanks again.