Stormin Mormon wrote:

Got a call today from a lady with a GSS201EMD WW GE
refrigerator. From a net search, EMD might really be EMB.

In any case, the temp in the box isn't dependable. She had
someone out, who replaced the defrost heater. $250 later,
it's still not working right.

What's the common problem that goes wrong? And what to fix,
next?

Not familiar with that model. Does it have any motorized dampers? On my
GE profile arctica a motorized damper door broke and resulted in temps
too cold in the fridge side. If it broke in a different position it
could have gone too warm. At any rate the door was only available in a
complete assembly for like $160 so I fab'd a new door in my shop for
about $5 and 30 minutes. It's worked fine for 4+ years so far.