Hi all, I got a good deal on a used Fender Rumble 200 (in "excellent condition") from GC. I haven't played through it in a while and last night I noticed that i was getting no signal, and there was no sound coming through the speakers. Importantly, no sound would come through the headphone output either (ruling out a problem with the speaker itself). After a little while, I managed to get it working by fiddling with the angle of the 1/4" cable in the input jack. I haven't been able to replicate that sweet spot since this morning and the amp is essentially dead again. Do you think this is a problem with the input jack? If so, how can I fix it?