Problem with VIEWSONIC P-810 monitor

[grandchehaw]

I just recently purchased a used Viewsonic P-810 monitor off of the
AnandTech boards for $150. The monitor still has a great picture and
no burn in at all. The screen and case are both in great shape as
well. About a week after purchasing the monitor is started to make
this poping noise and the screen would enlarge outside of the monitor
edges and then a minute later it would adjust is self back. I
contacted the previous owner and he mentioned that the monitor is a
little humid sensitive. He said when it was in his basement he would
have some problems but when it was upstairs it would work fine. Just
my luck my computer area is located in the basement. The seller has
offered me a full price refund. My question is what would be causing
the monitor to do this? Do you think this monitor can be repaired or
should I just get my money back and look for another monitor? Just in
case this makes a difference this P-810 is the verison that has the
BNC type connectors as well. My father has the version without the
BNC connectors and it works great.

TIA
-JR