Dimension 2350 CPU Heatsink Retention Bracket Broken

Hello,

I'm now to the forums but not new to computer hardware. For some time now, my sister has been complaining of her Dimension 2350 being slow and more recently, powering off with no warning. Once I returned home from college for Christmas break, I opened up the case, and swung the green shroud out to inspect the heatsink assembly. Upon rotating the shroud outward, the heatsink literally just fell off. Trying to figure out why, I noticed that the retention bracket had two broken peices where the brackets grab hold to (what do you expect from plastic?). Anyway, I igured not much of a big deal - just get a new retention bracket and we're golden. After a little bit of searching at the local computer shops, I had to go online to buy a new one.

Earlier this week, the part finally came in and I put it on the motherboard, however, after I took the old thermal pad off and clearned the CPU and heatsink base and applied some Arctic Silver 5 thermal paste, I found that when I put the heatsink back into the socket, it does not touch the CPU. There seems to be too much of a gap.

I didn't come here just to tell a story, I promise. I have a question, too. I have been looking at some CPU thermal pads online, but unsure of the thickness requirement for it to fit. Does Dell provide any?

FYI, the exact retention bracket I got is this one: http://www.pcloft.com/pe4so478remo.html

I can update this thread with pictures of the system, if necessary.

Thank you and have a Merry Christmas, all!