[GTALUG] war story: the end of an old computer.

[D. Hugh Redelmeier]

| From: D. Hugh Redelmeier <hugh at mimosa.com>
| Date: Tue, 26 Jul 2011 01:54:39 -0400 (EDT)
| Subject: war story (spoiler: dying power supply takes disk drive with it)

Another war story.

| I replaced the power supply with a CoolerMaster RP-650-PCAR that I
| happened to have in inventory.
| 
| Still no joy.  When I turned power on, the CPU fan would jiggle once but 
| there was no other sign of life.
| 
| When I unplugged all the peripherals, power seemed to work.

I have a similar symptom in another computer.  I narrowed it down to
the motherboard: when everything was removed from the MB (all
connections) and it was placed on a non-conductive table, with a new
power supply, I got the same behaviour.

Since the computer is about 8 years old, it isn't worth putting a lot
of time into fixing the motherboard.  So I stopped diagnosing at this
point.

The reason I mention it is to hightlight that the symptom (when power
supply plugged in, the fans start up but shut down after a second or
less; case fan spins slowly) seems to be non-specific.

When I first encountered the symptom today, I went back in my TLUG
archives because I vaguely remembered having posted something with
this symptom.  Too bad that the old posting turned out not to be
useful.

For the curious, here is more of the old posting:

| A process of elimination showed that the problem came up only when I
| connected one of my Seagate 7200.11 drives.
| 
| It seems that the power supply death agony caused the 12V TVS
| (<http://en.wikipedia.org/wiki/Transient_voltage_suppression_diode>) to
| blow.
| 
| I was able to get the disk working again (and the data recovered) by
| removing the dead TVS.  See
| <http://forum.hddguru.com/help-with-disconnecting-tvs-from-seagate-barracuda-7200-t15313.html>
| 
| To get at the TVS, I needed to remove the drive's PC board.  That
| required a TORX T6 tool which is moderately hard to find.  I got one
| at Lowes.
| 
| I measured the resistance (DVM on 200 ohm scale) across each TVS and
| found it to be close to 0 on the 12V TVS.
| 
| I poked at the 12V TVS with a fingernail and it came off.  I guess that that
| means that the circuit board was slightly fried there.  But the drive
| now works.
| 
| I don't know if the TVS ever protects without sacrificing itself.  I
| imagine that it does.  So I should probably rescue the data and treat
| the drive as junk / unreliable.
| 
| Since the power supply warranty is only 3 years, I probably cannot get
| anything from Antec.  Since the power supply killed the disk drive
| (and I did an operation on the drive), I don't see the drive being
| covered by the Seagate warranty (the drive was purchased on the last
| week that Seagate offered 5 year warranties on OEM drives).
| 
| But I'm mad.  I think that Antec should have recalled the power supply
| when they knew of the bad capacitor problem.  (I haven't broken the
| PS's seal so I'm not sure that this is a bad cap problem.)  Time for a
| class action suit.  But I'm lazy.
| 
| Anybody had experience with hidden warranties from Antec?