Dell monitor

I have a Dell Dimension 4600 computer wireless mouse and keyboard with a
factory 1801FP monitor (Purchased in 2004) and a BFG 6600 AGP video
card..The monitor has started going to self test mode after all night in
standby mode.
I do the monitor reset in the morning and everything works again until the
next day when I have to reset the monitor again. No problems all day long
with the computer or monitor.
I did find a week ago that the usb ports on the monitor failed to work so I
use the computer ports now.
Is my monitor on the way out? Could I have a problem with the video card?