ScuzzBlog: Diaries September 2021
Entry 20th September 2021: Post 1: Amiga 1200 PSU - What lurks below.
Amiga 1200 PSU - What lurks below.
First up let me say that I never use the original lightweight PSU
on any of my Amigas. I gave up using them in 1994. So they are
either stored inside their original box or in a large plastic bag
inside an old Amiga monitor box deep in a dark store. These things
never see the light of day.
I did have cause to test the one unit shown here but given that it
caused the Amiga drive light to flicker it was quickly returned to
the store never to be used again. That was in 2017.
The first PSU dates from 1995 and was included with an Escom A1200HD
Amiga Technologies Magic Pack. The owner cut off the power supply
for some reason and it has always looked like this. When I opened
the thing up it was leaking yellow 'goo' [ technical term ] and
was in no condition to ever be hooked up to an Amiga.
The second dates from around 1993/94 I guess and instead of having
the leaky capacitors at the front end, has these white slab like
components. However the board base has been taking a lot of heat
and this may have caused one of the slab blocks to overheat and
fail.
This PSU had the thickest spider nest inside. And yet it had been
in a bag and stored in a dark cardboard box. I never use these
units. It really is incredible where spiders will take up home.
What exactly they live on I do not know.
Either way I am so pleased I chose never to use these style of PSU.
Even back in 1994 they were incapable of powering an expanded Amiga.
There are heavy weight smaller PSU units and I do have one of these
on my A500 in the disk room. My guess is the case is filled with resin.
That one does work without fault. The A500 bricks have served me
well and I don't have any hang ups continuing to use them. I did
manage to get one to catch fire, but that was on test having developed
the killer 'drumming of death'.
Finally, I featured a lightweight A500 brick failure some months
back which puzzled me as to why it burnt out. During my routine
checking of supplies and circuits I discovered the switched connector
to the socket had a dodgy circuit which was shorting when switched.
I am sure it was this that caused the short and not the failure
from any PSU component on its own.
PS I am no electrical engineer. So please check that your PSU is
safe before switching on. And just a tip... always have your machines
on a surge strip and switch it off when ever plugging anything in
and out. My circuits are always dead when I connect or disconnect
anything. I also have all my circuits on dead end switches with
neon indicators. When the lights are dead then so are the circuits.
Never leave live circuits connected to PSU units or monitors. So
often you think stuff isn't still live... but it is when connected
to the mains, even when switched off. Kill the power and not you or
your Amiga. And NEVER EVER hot swap connectors or power to an Amiga.
And that includes any item connected to a port, whether it has a
live pin or not. Make sure your circuits are dead. Leave a good
fifteen seconds before doing anything which has been powered. Longer
is better.
Stay chill and avoid the risks. Think before you live anything up.
Amiga 1200 PSU - What lurks below.
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