Grundig g5 oscillation problem

[W3RSW]

Hi all,
I have a g5 which has worked well, esp. With phones, bedside, outside, etc. for four or five years. Lately it's gone into various fits of oscillation, at first raspy, cutting out all am and ssb, all freqs. and thru resets, but allowing FM sort of through.  I noticed that after being idle, say overnight, it would recover. This occurred with freshly charged or new batteries, using the wall wort, whatever.
Progressively got worse and even covered up the fm band. 

So I put it in the refrigerator to verify it was a warm up to room temp. Problem and it is. Now it won't even play normally unless 'frozen' to refrig. Temps.  Guess I zapped it; should have put it in oven.

Possibly a minute board crack or lifted smt solder joint.  Hopefully not the dreaded uProc.
Anyone experience this or similar.? Searches yield everything but...