ScuzzBlog: Diaries April 2021

Entry 4th April 2021: Post 1: Amiga 600 - PC2AM the A600 killer.

Amiga 600 - PC2AM the A600 killer.

I have had the most dreadful couple of days. All started very
innocently when I found this old network cable software PC2AM.
With the cable provided you get two disks, one for the Amiga and
one for the PC. You then connect the connectors to respective
parallel port sockets on PC and Amiga. Run the software on the
PC which mounts a drive icon on the Amiga.

Point of note. Last time I used this back in 2005, a Compaq PC
I was using locked up and never booted again. I had been using
the software and cable for a good time and found it slow but
pretty useful. It prompted me to install an Ethernet cable for
faster speeds so I never used it again. The Compaq has its own
operating system that is locked behind control placed by Compaq
which only lets authorised dealers tinker with it. I recently
found the Compaq in the loft, just dumped there.

Back to the A600. I followed the instructions to the letter and
configured the PC after installing cables, and only then switched
on the Amiga 600. I had installed the Amiga software AMI-PC but
found absolutely nothing on the PC floppy. So I had to dig out
a backup copy and rebuilt the disk. Next I clicked the execute
file on the PC and that is where the problems began. Instead of
a mount file on the Amiga I was greeted with the mouse pointer
locking up.

I rebooted and started the process again, but found within a few
seconds the mouse pointer would lock up. I very quickly powered
down and unplugged everything and booted the Amiga. It was then
that I realised that within a few clicks of the mouse the mouse
would become unresponsive and then freeze. I could do nothing
with it. Not even the Amiga keyboard mouse keys worked.

Time to strip her down to basics and see if the motherboard was
OK. IT GOT WORSE.. Much worse. As I lifted the hard drive 2.5"
ribbon connector out came three pins. I lost three pins rendering
the hard drive useless on this machine. Why ? I do not know. I
could not have been any more careful when taking out the connector.

So I was now down to the motherboard and she was just the same.

I took high res images of the board and capacitors but found only
one dodgy location to a C321 which was to the audio connector.

I brought to the machine an external drive and a port utility to
check the mouse and joystick. This I was able to click open before
the machine froze and the clicking and movement was OK on each of
the ports. Whilst I used the utility the mouse did not freeze. But
as soon as I tried to click another icon it locked up.

I then loaded and played a series of games and she worked without
fault. I could even play Lemmings which is all mouse driven and
she worked perfectly. So the fault is a timing issue where a gate
is being closed down after a series of clicks and then shut down
completely. I checked virus issues swapping disks between three of
my other Amigas but could not replicate the issue.

So there is my problem. The computer has no mouse after about ten
clicks and I have no idea why. It could be a capacitor I suppose.
I sense it's a graphics issue like I had with the Denise on the
A500 Plus. Could also be a CIA. If a component had failed like a
resistor the problem would occur all the time. Feels like the
trains are colliding with another process and that points to a
chip problem.

Sadly the A600 is all surface mounted. I am not an electrical
engineer and never claim to be one. This is a job for an electrician
and so she is going to be bagged up and placed in store. Maybe
one day an electrician can fix her. One thing is for sure I will
like never be using that parallel port cable again. It's lethal.

Really could do without days like these.

UPDATE !!!! April 5th 2021 . See last image for latest update.

Amiga 600 - PC2AM the A600 killer.

SCRUB THIS... Not even close.

Update 5th April 2021

The problem is actually a keyboard issue
and the failed capacitor here has damaged
the keyboard reset circuit. Consequently
a few moments warm up when the computer
switches on the capacitor fails and there
is a log-jam of instruction causing the
computer to lock up. A partial reset
without the reset.

Solution is to repair the damaged track
and replace all three capacitors.

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Last updated 5th April 2021

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scuzzscink 2021