Unsticking a Seagate ST-419 head

[Jason Howe]

On Thu, 20 Oct 2016, Mike Stein wrote:

> I've got several ST251-1s that spin up just fine, no funny noises, but then do a bunch of back-and-forth seeks and shut down again.
>
> It's the usual, "they worked fine the last time;" any ideas what the problem is and if there's anything that can be done? Presumably it's having trouble finding the sync track; weak signal? Any ideas?
>
> m
I'm actually trying to bring an ST251-1 back to life right now.  It 
worked, then was intermitently not recongnized by the controller after 
being powered on for a while, now not recognized at all.  When you apply 
power it runs through whatever standard head-sweep routine (self-test?), 
but there seems to be a communication breakdown between the Drive 
electronics and controller board.

Various sources on the interwebs suggest me that the small SMD tant caps 
by the power connector are a known issue on these drives and can lead to 
all sorts of flaky behavior.

I've orderd a few from digikey, hopefully will have them by this weekend 
to attempt a repair.

See my forum post here, where my shoot-in-the dark analsys is disagreed 
with: 
http://www.vcfed.org/forum/showthread.php?54516-Caps-for-an-ST251-1:

--Jason