"Gareth Magennis" wrote in message
...
Hi,

I have a Roland drum machine in for repair. The machine powers up and
goes
through the Operating System upgrade, up to the point the Flash is written
to, where it fails and the unit will not boot, showing a "damaged memory"
warning. I suspect the Flash chip is faulty.


When I informed the owner of my findings, he then tells me he thinks it
was
damaged by a PAT test. It is powered by a Wall Wart, and he thinks it was
plugged into the unit during the test, as it stopped working immediately
afterwards.

An internal inspection shows around 10 caps around the internal power
supplies are bulging and have leaked guff onto the PCB. The 3.3v rail is
at
over 4 volts, so presumable the regulator is toast.



So, if you PAT test a Wall Wart plugged into a unit and turned on, what is
likely to happen? What I have just described perhaps?
Or did someone just use the wrong power supply instead and isn't letting
on?



Cheers,


Gareth.

Over the years, I've seen a lot of items from schools and commercial
premises that have odd microprocessor-y problems, and a recent PAT sticker
on them, so I'm certain in my own mind, that these have suffered damage as a
result of either inept or inappropriate use of a tester. The items in
question, are often boom boxes that are double insulated, and have a
removable figure 8 power lead, so there is absolutely no point in applying
these tests, anyway. As to wall-wart powered stuff, I can't recall ever
seeing an item that may have been damaged in such a way, but if other items
with a similar small power transformer fixed internally can suffer, I don't
see why it shouldn't also be the case for an externally powered device. I
think, however, with the bulging caps you say you've found, in this case
it's probably either a wrong power supply having been used, or just general
failure, rather than a PAT issue. Is it from a school ? If it is, it's
probably either left on all the time, or subject to dopey kids and teachers
digging it out of a cupboard in the music room, and jamming in the first
power connector that fits, and appears to make it work ...

Arfa