Overheating cpu an frying motherboards!

[Dyentious]

Well, I really need some help with this one. I have an 1.6+ ghz AMD Athlon processor, with an Elitegroup K7S5A motherboard. I installed this with only one problem, and that is that the computer would lock up in windows all the time if i had the cpu frequency set to 133, as opposed to 100. So, I set it to 100 and everthing worked fine.
The System ran perfectly for about two weeks, and suddenly it locks up. After realizing something was very wrong after trying to load up windows, I check the BIOS and the CPU temp is 175 degrees F. So, I turned off the computer and let it sit until it was back to room temp. I turn on the computer, and go directly to the BIOS to watch the cpu temp on the system monitor, and it slowly crawls from 95 to 180 F over about 4 minutes and then shuts itself off. I was told something happened to the motherboard, so i bought the very same motherboard again.
The cpu temp was fine at first, and the system ran great again, until about a week later, when it locks up, and the cpu temp is at 180 again. I have a thermaltake cpu fan, and it is installed and working properly. I'm not really sure what to do next, because I don't want to have to keep buying motherboards over and over.
Does this have anything to do with the cpu freq set at 100 instead of 133? Should I just buy another motherboard and some new cpu thermal paste and reapply it with a bigger cpu fan?

Please help!
Dyentious

[homer15]

are you sure the heat sink is making a good thermal bond with the cpu? what did you use to bond them together?

[glc]

Are you positive the heatsink/fan is installed properly? To get THAT hot either the fan is stopping on you or the heatsink is not contacting the core properly.

[Cricket]

Hi Dyentious,

Which Thermaltake heatsink/fan unit are you using? Orbs look cool but aren't very good at cooling the CPU core.

Make sure the heatsink is sitting flat and level on the CPU core. The metal clip that holds the heatsink down should make contact with the heatsink directly over the CPU core. Are you using a thermal pad or thermal compound of some kind on the heatsink and CPU core?

What kind of case are you using...micro-tower, mid-tower or full-tower? Do you have case fans installed in it? At least 1 fan on the lower front blowing in and 1 fan on the upper rear blowing out?

Cricket