memory upgrade problem

I'm new to the forum, but I have done my research and now im am stuck so I thought I would ask for help. I just went to CompUSA and bought a stick of CENTON 256mb sdram pc133 144 pin RAM thinking I would have no problems but after I installed the ram and turned on my MPC 1000 I just got a blank screen. I then turned off my MPC 1000 and turned back on and held down the Window button and got the Boot on OS mode, and I noticed that it did indeed recognize the 128mb of ram, but my screen is BLANK Why?

Sometimes installing the ram messes with the contrast setting of the screen.
Try holding down shift and rotating the data wheel in one direction or the other till the screen shows up.

I tried and nothing.