OK, first of all the A37 is reasonably ancient now, so you don't have to worry about the
warranty.
And it's either going to be an electrical problem, or a mechanical
one.
If it was me, I would carefully take it apart, give it a thorough clean,
and put it back together again. It might be a piece of dirt or something sticky
interfering with the problem key. If that doesn't fix it, then you have to decide whether
it's worth spending the money on getting it repaired, or putting that money towards a
replacement.
Andy
--------------------
When the going gets weird, the Weird turn Pro.