Curtis Mathes 27" TV

Question

My Curtis Mathes 27" TV Looses its picture and sound every so often.  It seems like a conflict with the front panel A/V out.  I tried soldering extra A/V out jacks in the back but that only made the existing jacks a little more reliable.  On the front jacks, it seems as though by tapping the A/V wires/plugs it makes the picture come back.  Thanks for your help.