I agree with Shadow, the most common random read error is cabling. Usually read error's are data cables, bad memory, or bad motherboard capacitors for the power supply circuits.. Cables from the PSU have small round connectors inside that commonly stretch out in diameter then become loose, the slightest vibration harmonic will cause the connection to "float" between the pin on the hard drive plug long enough to make the drive get a data read error, or click on and off several times. The cool thing is the molex connector rounds can be smooshed back together with a small flat head screwdriver or the point of a voltage probe stuck between the plastic shell and the outside of the round connector. Another common read error is caused by Over/over clocking the FSB.
