asus p2b rev. 1.04 only two short beeps...

It's an old comp, I know. But with some jobs to do. Asus p2b rev. 1.04.

I only get some beeps (two short ones), and no videopicture and even no
post. The video card , the monitor is oké.
(When I look for the meaning of the two beeps, I read "Parity circuit
failure", but the memory is in for ages without problems.)

At the moment I really don't know what more relevant things to give. Can
somebody give me a clue how to fix the problem?
I Would be very pleased. Thanks!

Kind regards,

Henk