ScuzzBlog: Diaries August 2019
Entry 17th August 2019: Post 01: A1200 - First flicker of failure.
A1200 - First flicker of failure.
A few years back I managed to salvage a couple of hard drives
and having done so I placed them in Amiga 1200s to check. The big
problem with the 2.5" drives is the issue of sticking read heads.
So many of mine that I left for some time finally locked up. So
as a matter of ritual I endeavour to test machines with drives on
a regular basis.
The problem I have is that with so many computers it is not possible
to have them all hooked up to monitors. And so the two that sit
behind me here to test hard drives have no monitors connected.
The summer has been so hot for long periods and I have a policy of
not using computers when the temperature rises above 30/31 degrees.
So when I got round to testing these two computers last week I was
a little troubled that the power light was flickering on and off
and eventually going off completely. So I used the computer for
the Sensible Golf feature with a view to checking the motherboard.
So late yesterday I stripped the motherboard completely out of
the 1200 and gave it a general clean with cotton buds before taking
pictures today. Sadly what I discovered wasn't that good. There
were three obvious issues. The first is that the TV modulator has
a rusty shield case. When I say rusty I mean rusty. If there is
anything in the box that is leaking I cannot get to it as the
small PCB on the top is soldered in place. The case is very rusty
though remarkably there is no residue on the adjacent motherboard
or under the motherboard itself. There is a large hole under the
modulator board and yet nothing has seeped through.
Next there are two locations on the board where it appears obvious
that the circuitry or tiny chip legs have degraded by being attacked
by some substance. It is not obvious where that substance has emanated
from but it appears clear that something has leaked.
Worse is that the screen display has an ever so slightly yellow
tint to it. Difficult again to pinpoint as the Workbench screen is
set to a picture and this is in a yellow shaded pattern. Or so it
would appear. My eyes may be playing tricks with me but I sense
that the blacks are seeping a yellow ghost and that could be a
chip issue that has been triggered by a failing capacitor. My guess
is that there is a capacitor issue with the computer.
As to the dodgy light, well that was easier to diagnose. I did
first think that the computer had a power problem until I simply
wiggled the LED light support and the light came back on. If I
simply press the board with my thumb the light comes on. There
appears to be a dry solder joint that is causing the issue.
I thought I knew the history of this computer, but I am not so
sure now. I tend to put labels on trapdoor covers. Thing is I
can use the covers on any Amiga. I am convinced this is not the
computer referred to as the Apollo machine had a rogue pin
soldered in the corner, and this computer has none. So as to
the A1200s origin I know not. I have no idea how it was stored
or used, or the state it was in when it arrived. I continue to
test the drive but sense this machine does need those capacitors
replaced. Dunno.
I have failed. Doesn't make me feel very good. Never mind.
A1200 - First flicker of failure.
Check out the surface damage to legs/solder joints.
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