CPU heats up too fast to update BIOS

[Tranq]

Motherboard: Epox EP-5EPA+
CPU: Intel Pentium 4 3.4 ghz 1 MB L2 cache

I just built this computer a few days ago and it was running fine with the thermal pad that was provided on the heat sink with the CPU but as soon as i put some sort of load on it like playing a game...the fan started going crazy rising to around 4,600 RPMs and the temp of the CPU went to around 160 fahrenheit. So, I decided to remove the pad with some 91% isopropyl alcohol and put some arctic silver 5 on...after putting the arctic silver on the POST reads the CPU temp to be going up to 185 degrees and it shuts down the computer automatically. I cleared the BIOS so my setting of auto shutdown on 140 degrees was disabled. I'm sure this reading is wrong though...I ran the computer open and put my hand around the heatsink as the POST was reading temperatures around 180 degrees and i could just feel a little hot air but nothing even close to that temperature...I'm sure i need to update my BIOS but i dont even have enough time to boot windows before the computer shuts down...any ideas?

Thanks

 

[Samstoned]

I looked at the board
can't tell if the temp senser is mounted right on MB or is stuck to CPU and has plug
if it is plugable unplug it,I have not seen any mention of this issue with OH.
EPOX makes a good MB I have had a few of them.
if you are putting your finger on heatsink and it is not contacting surface correctly it would in fact not feel hot ,but the cpu would burn up
I'm goofy I polish the CPU and heatsink shiny use very little thermal paste.
I don't think its the PSU at this point ,if you have a spare try it see if it helps.