line out sound interrupt

Good day fellas.

Get used XL and constantly the sound just lose like some contact inside mpc is depart of plate.
I need to push mpc screen or case hard down everytime to get sound without discrete.
It's only about line/headphone outs.
If I get inside of mpc, what I need to look and where?

The problem could be the main output board. If you're up to opening the unit up, check the ribbon cable from the CPU board to the output board. Disconnect and reseat it to make sure you got a solid connection.