9200T going for landfill

In message en.co.uk,
Roderick Stewart wrote
In article , Mike Tomlinson wrote:
I've just looked at an external SCSI DLT tape drive. That had bad caps
on the 12V output of the PSU, causing it to rise to 20V under load. No
overvoltage protection was fitted.

Can you explain how a faulty capacitor makes a voltage rise?


On Topfield PVRs a faulty capacitor causes the 5V line to go low. The 5V
is used as a reference for nearly all the other power rails and the
switched mode supply drives harder to try and get the 5V correct and in
the processes drives all the other rails higher.
Typically the 5V being 1V low takes the 12V line to 17V and the 30V line
to 37V. These elevated voltages often kill hard disks and tuners.

--
Alan
news2009 {at} admac {dot} myzen {dot} co {dot} uk