Meet the hero
Date: Monday, February 05 2018 @ 16:26:22 UTC
Topic: Amiga Repair & Restoration

Three years ago...

It was rainy day, I was driving my family to some party when I got a call from my friend who told me that there is one Amiga 500 on second-hand market. Something like that never happens in my city. I left my family on parking and start running. There it was, in the middle of the junk, Amiga 500 under heavy rain, dirty. It was so sad to see that. I took it into my hands trying to find a seller. Finally he approached and told me 10Eur. It is mine! Well, he could put any price I would still take it but he didn't know that. Later that day I got home and after some cleaning and drying powered the machine and it started to work without any problems. There is a question I dare to ask. Do you think that your modern phone or PC would be working after 27 years? Think not!

This Amiga 500 was used for creating Vampire 500 as we know it.
Amiga 500 S/N: 2169035 build in 1991.

Two days ago after more than 800 Vampire 500 V2 cards tested this machine finally died. I was so sad but after brief investigation I found out that only DIP64 socket is broken and that all electrolytic capacitors needs to be replaced. So not huge task you may say but problem was to find original DIP64 socket and I had to use original one because of proper alignment of headers used in Vampire cards. Luckily I had some DIP sockets with different pitch but with same metal connectors inside. So I just took those replacing broken ones inside DIP64 socket.

Capacitors were another story. I live in the place where is very hard to find anything so most of the time you have to order online and patiently wait for 2 months to get the package. Often after so much waiting you realize that you didn't get what you paid for so you have to start all over again. Trick is to think in front what part you will need for some project you will be doing next year.
Over the weekend I found 2 shops in my country who could have what I need. One of them was in my city and another about 100Km away. I woke up early and visited my local shop who was closed at the time they should be working. Right about when I decided to have road trip they showed and sold me capacitors. Yes, they had them. I was lucky and persistent waited for over 2 hours for them to open the store.
Most of the capacitors on the motherboard were nice looking not showing any traces of damage. However measuring revealed that they should be replaced. Over the time capacitance and ESR values changed a lot.

On the left side of the picture above is original capacitor from motherboard rated at 100uF, 16V. Capacitance was lower and ESR value more than two times bigger than it should be. Right side of the picture shows replacement capacitor rated at 100uF, 25V with ESR 0.78OHM like it should be according to shown chart. In total 17 capacitors needed to be replaced.

Purpose of this article was to write down serial number of this Amiga because this is the machine who took so many beatings over past three years. It is the machine who gave us Vampire accelerator and bright future to the Amiga. It still lives and I hope that it will live for next 27 years.

This article comes from Amiga FPGA Accelerators

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