iMac constantly putting itself to sleep after HDD upgrade

[xkmkmlmx]

Mid 2007 iMac keeps going to sleep after HDD upgrade.

I recently upgraded my imac's hard drive to a 2tb drive from a similarly speced 1tb hard drive, both installed by me.

After installing snow leopard and getting everything back up and running, it started to crash/sleep every so often. And then it started doing it every 2 minutes. Thinking it might be a heat issue, I got temperature monitor installed. I immediately received readings that were 'off the charts'. An average reading of about 125F and some readings saying they were as high as 165F.

The iMac had been on for a few hours already, so I immediately just did a quick hand test all over the case. No more warm in any area than ever before.

Any ideas?

I have not ran a hardware test yet, but I have reset PRAM and the like. No difference.

Could it be that I didn't connect the heat thermometer back up correctly? Or that I placed it on a bad spot on the HDD?

I am going to open it up in a little while and see what is going on, but I wanted to see if anyone had any thoughts before I went ahead.

 

[Detrius]

What temperature readings are you referring to? CPU? Hard drive? GPU?

If you forgot to plug a temperature sensor in, the SMC takes the safe course of action which is to run the fans full speed. However, the software might register it as an extremely high temperature.