Patrick,

Thanks for that tidbit. I checked the +12v rail on the motor board at the + leg of the 470uf cap... less than 10v when the motor is speeding up, and 11.2 when running. Power coming into the drive is 12.04, so I don't think this is a PSU problem. If I jumper the 12v rail on the motor board to the 12v test point on the controller board the voltage comes up nicely. 

Of course now that I'm looking at the drive in more depth it's not going into its failure mode. I might replace the 470uf cap on the motor board for good measure, and see if the problem comes back. 

Thanks, 

-J

On Mon, Feb 20, 2017 at 5:50 PM, PSchaefer <dr.p.schaefer@gmx.de> wrote:

Am Montag, 20. Februar 2017 04:32:54 UTC+1 schrieb compu_85:

After the drive as run for a while the head break will suddenly click on. Of course the drive stops responding at this point. 

I can also hear the disk RPM changing after this happens... sounds like it speeds up, then cuts the motor off for a moment, then comes back on..


Check your power supply. This happens when the 12 V line is weak or has excessive ripple.

From these power dropouts your drive may collect some bad blocks, but this can be healed by reformatting.



Best regards
Patrick
 

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