over dub button problem

I have a problem with the over dub button. It could just be me being an mpc noob and nothing actually wrong but seems weird to me.

when i press over dub and play it activates the actual record button and counts in. it will play the 2 bars with no sounds just like when recording over that track. once its played the 2 bars the over dub light comes one and i can then add sounds in over dub mode.

i have the mpc 2500 with latest JJ OS 3.10

without anything playing if i hold overdub down the record light comes on and the over dub light flickers a bit.

any ideas.

its not some weird jj os issue is it?

i know you can get replacement buttons but i'm not confident with my soldering abilities

sorted the issue.

I opened up the mpc and cleaned all the connections and also cleaned the ribbon cable and it seems to work properly now.