SWR LA15 input jack not working

[Big El Bass]

I have a SWR LA15 Bass combo amp. The input jack where I plug my bass in, doesn't work, well, barely works. When I wiggle it a little, I get some sound, but it doesn't stay working> It is acting as if there is a short in the connection, but when I open it up, nothing appears to be disconnected. Could it be the input is just bad, and if so, is there a place where I can buy a replacement part?

[Jazz P Bass]

First item on the agenda should be to 'touch up' the solder joints.