NoPro

I have a fender Princeton dsp 65 amp. It works 90% of the time. If I hit the top of the amp its fine. I use it as a go to... testing guitars etc.. fun amp and convenient (not recording) amp. It's solid state. I have a few small tube amps for recording and for when I'm serious about tone and recording. Here's the thing .. It's good to have a solid state amp for variety. I jiggled the speaker cables..they seem well connected. I'd like to keep it but I'm broke. Anyone know what to do to try and fix it. Maybe it's something with the digital effects? I'm not experienced with amp repair. What's reasonable to pay to fix it? Should I sell it for parts ..the speaker? Any help appreciated.