Machine Info: 20" Intel 2.16 GHz iMac (white).
My Background: I've taken apart many Macs and am comfortable with this type of repair. This is the first time taking apart the intel iMac (a bit of a pain especially compared to the early G5 iMacs which are very simple).
Replacement Notes: When disconnecting the Hard Drive Sensor from the logic board, one of the four wires on the connector came loose. It seemed to go back into the connector fine when I put it in. Before I put the new drive in, I did a clean install of Leopard and then updated it to 10.5.6. Some of the EMI tape on the sides of the screen weren't put back exactly as it started out (it was a big pain) but I did a decent job.
Problem: When I put the computer back together to test it, the screen would have occasional anomalies, but opening a window and moving it over the anomalies erased it. The computer would occasionally freeze (not running anything) even shortly after start up. I put it aside for a day (to work on other projects). Before I turned it on, I reset the SMU (I did not do that before). Now when I turn the computer on, it seems to work fine, except the fans are going at high speed (immediately at startup and for the whole duration the computer is on).
Questions: I could understand that the fans would be related to the hard drive sensor (and hopefully replacing that will solve that) but I would think that should not have had the initial results (screen anomalies and freezes). What other things might be causing the problems? What else should I check? Is it possible that the hard drive sensor is not the problem? What should I do now (before ordering a replacement hard drive sensor)?
Thanks!