koitsu Premium,MVM join:2002-07-16 Mountain View, CA kudos:19
Thanks -- standard 4-pin Molex indeed. All it provides is +12V (yellow) and +5V (red). Both black wires are ground. No 3.3V, but that's not necessarily damning. I wonder if that Seagate drive uses 3.3V for the underlying PCB circuitry (e.g. processor that controls the chip that controls the spindle motor) while using 12V or 5V for the motor itself.
This problem is very strange. I'm adding it to my list of "weird mysteries" that I don't have an immediate answer for. I wish I could say with 100% certain a different PSU will solve your problem, but with the information I have (not your fault!) I can't say that for sure. -- Making life hard for others since 1977. I speak for myself and not my employer/affiliates of my employer.