New power supply doesn't fit into my ps3 slim?

Hi,

I recently bought a new power supply for my ps3 slim off ebay because the old one stopped working. I have taken the ps3 apart and taken the old one out but the new one doesn't fit flush into the ps3. I have attached both cords that plug into it and got power which is good but I believe the problem is that two metal rods that are supposed to slide into the power supply from underneath are not lining up properly with the slots there are for them. The old one fits perfect which makes me think it might be a slightly different model (It fits the space, just doesn't slide in). I was wondering if these two metals rods were important (maybe for earthing or something?), I don't know, but could I get away with just connecting the two cords and not putting the cover back on the ps3 (because it doesn't fit if power supply isn't flush). I know this sounds really confusing but if someone can help me out or knows what the rods are that would be GREAT!! Thanks!