When I turn on my Optiplex 960 is starts making two noises, one a high pitched shrill sound, the other a pulsing/clicking noise that sounds like it's generated electronically.  The power on light is blue, the error lights showing are 1 4.  I've run the diagnostics (and the noise stops when I go into the diagnostics/setup mode), and get an error for a Drive 3.  Since I only have 2 hard drives, and one CD/DVD player, I don't know what Drive 3 would represent. 

The other diagnostics pass, but I didn't run the 30 min memory tests, only the shorter ones.

I've put my finger on the two fans I can see (large vertical fan for cpu and the graphics card fan) and briefly stopping each doesn't change the noise.  I've unplugged(power and data) the two hard drives but the noise continues.  The noise(s) seem to be coming from the center, in the area of the CPU.

The power supply lights in the rear are normal color(green?).

The computer only boots up part way(about one inch of the on screen bar) and doesn't go past that, never  reaches the Windows XP screen.

 

I've read that 1 4 error lights indicate a bad motherboard.  Is this correct, and why would the diagnostics still run if the motherboard was bad.  Are there any other tests I can try to isolate this problem?

Thanks in advance for any help with this...

 

John

If you email me, use  , that's the upstairs computer I'm on now.