Hi all, I once resurrected my Seagate hard drive by using the hyperterminal guide. It all went well after that but has failed again a few months later ( not being recognised by bios). I tried the routine again but it failed performing the Spin Up command. Now I can't do anything with it.

All that happens is that the motor is receiving short voltage pulses to the spin motor (each half second On-Off-On-Off). On an old sata drive I am measuring +4.7V on each of the three pins of the PCB to the motor, with respect to ground. I want to test the spin motor by using an external power supply. Would I need to connect a 5V supply to ALL three leads to test spin or just one or two. (I'm thinking that maybe one of these leads are used for a type of feedback for revs monitoring or something.

Anyone's input on how this works is most appreciated and you can get as technical as is required, thanks.

Measure the resistances between each pair of motor terminals. There should be three phases. The resistance of each phase winding is about 3 ohms, so phase-to-phase should be about 6 ohms.

See the following datasheet for information on how to drive the motor.

L7250, SMOOTH, spindle motor + VCM controller, ST Microelectronics:
http://www.datasheetcatalog.org/datashe ... Xyuswx.pdf

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