Dimension 2350 RAM

I just pulled this old beauty [Dimension 2350] out of the closet and wanted to see it run and what was on it. I got the Memory failure code (A&B lights yellow). The RAM in it has no stickers so I tried to look up what it is compatible with. What I saw said that 512MB DDR PC2100 or 2700 would work. I now have a Samsung PC2100R-25331-Z installed and I'm getting a Memory configuration or compatibility code (B&D light yellow). Could someone tell me what I'm missing here because I am not very skilled at any of this.    Thank you very much for any help!!