"CMOS" wrote in message
ups.com...
thank you for all replies.

The VGA cards i used are different. im sure its not a problem in the
video card.
The fluctuation is not small. it about one inch !.


Definitely sounds like poor regulation. Usually a small fraction of an inch
can be noticed on some low end monitors, but an inch is completely
unacceptable for a monitor indicative of either a dismal design or a fault.

can that problem be repaired ?


If it's a known design fault on that model, probably not without a service
kit, if one is even available. An inch really is very bad though, it sounds
like a serious problem. I'd take it back and insist on a replacement.

Dave