ScuzzBlog: Diaries July 2019
Entry 7th July 2019: Post 01: Amiga 600 - Busted Motherboard
Amiga 600 - Busted Motherboard
The title of this blog sounds a little fatal. Those that follow my
activities know that a while back I salvaged the motherboard that
sat in this machine and used it in another 600. To understand the
history of this computer we have to go back even further. A long
long time ago I bought a bashed up A600 real cheap and discovered
almost everything not working. No mouse port, broken floppy drive
and so on. I then bought off Ebay another broken Amiga plus spare
broken keyboard and used all the bits to make one good Amiga 600.
Given that I have no electrical expertise it really is all I can do.
So what was left was a broken A600 with no keyboard connector or
floppy, no cables etc. That was the computer that I swapped out the
motherboard for, given that one of my most treasured A600 developed
a fault on the motherboard. Basically stopped working. Having
successfully transferred the motherboard I placed the broken A600
back into store.
I have been threatening for some time to have a look at the board
and see if I can identify any problems. I also wanted again to
photograph an illusive capacitor leak. I have yet to see a leaking
capacitor and I was kinda sure there must be one on this machine.
One point of note and that is that in using my capture device I
was able to use the composite on the A600 and use a laptop to not
only view the results but also to record what happened.
When I do this kind of investigation I always remove the motherboard
fully and check both sides of the board. If anything has leaked on
the top it may have found its way below. The kinda things I am trying
to find are broken traces and damaged board connectors and solder
joints. You can also see if the board has been tampered with.
So what did I find. Nothing. Everything was just as it should be. No
leaky capacitors. No dull joints. No corrosion. And no tampering. To
all intense and purposes this was a near perfect specimen.
Time to connect and see how she is. Surprisingly she fired up with the
boot screen. Both internal and external floppy were working and clicking.
Next I loaded a Workbench disk and it failed giving a disk error. Same
on the external drive. I tried PacMania and it failed to load past
the initial splash screen. Now if the computer hits a snag with a
chip my guess it would have crashed. It wouldn't have simply stopped.
I doubt it is the floppy as I tried three drives. Two internal and one
external.
So what is my prognosis. I haven't got a clue. So what would I do.
I would first swap out the ROM. Sadly I don't have another 2.05.
I don't have the keyboard connector anyway so I'm stuffed if she works.
The chips on the board were all getting warm except the ROM chip.
There is no visible damage to the board. So I will probably keep
an eye out for spare parts and then maybe have another go in a while.
So here are some pictures for your amusement plus some video. If
anyone can spot a problem capacitor among the pics I would be pleased
to know which one. I am so pleased to have replaced the Canon G7
given that I can now take good close up images again. Also the little
capture gismo is a great tool for checking the display on an Amiga
without a monitor. So useful.
V I D E O S
Amiga 600 motherboard - Clicking floppy drive
Active floppy drive - Boot screen
Amiga 600 - Busted Motherboard
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