Archive for December, 2011

My Amiga 500 (Some time later…)

December 6, 2011

Working Okay, just no mouse!

I was doing so well with the blogging! I even had a long list of Amiga games lined up ready to play, however, after just over 20 years of constant use, my Amiga 500 has developed its first fault. Not bad I’d say for such a well used and old machine. Still, Amiga gaming in the last 2 months has been pretty non-existent and I’ve been on a little research mission to identify the problem, and begin preparations to try to repair it.

First off, Amiga games and software I’m pretty comfortable with, opening up and poking around inside the hardware less so, still, always up for a challenge. The problem began when the mouse stopped working in Joystick Port 1. The buttons worked fine, but the cursor wouldn’t move at all. I decided it was probably the mouse that had given up, so I bought another off eBay, and had one kindly donated to me from another Amiga user, both of these didn’t work either.

Burnt Out R401 on my motherboard

Not wanting to be defeated I decided to open up my Amiga, I managed a peek at the motherboard, and, with a large amount guess-work and common sense, thought I saw what looked like a burnt out thingy-ma-jig near to Joystick Port 1. Turning to the interweb I sought help from the knowledgeable folks at EAB and Lemon Amiga, who asked me for more details and came up with a pretty conclusive point that the ‘resistor’ in question was burnt out, or at least no longer working, and would need to be replaced.

Some of the advice given:

  • Most common problem is damaged U15 chip but first check mouse port +5v pin. (Mouse needs +5v, joystick don’t)
  • Problem has to be missing +5v – Check resistor R401 first.
  • Swapping CIA chips

U15 Chip and Resistor (Not my board, illustration purposes only)

The problem seemed to be the R401 resistor, I now need to repair it.

For this I’ll require:

Replacement R401 resistor (4.7 Ohms)

Soldering Iron

Solder

Steady hands

Lots of luck

Joystick gaming, repairs to follow!

This post is coming to you before the repair, as you can see from the pic, my Amiga still actually works and I can play games using Joystick Port 1, like James Pond shown. However, I love playing point n’ click adventures amongst other games and software, the mouse is pretty essential to me and I need to get it working, especially as some of my favourite games require a mouse (Hunter, Monkey Island, Sim City, The Settlers) Depending on how succesful the repair is, you may or may not see a follow-up post to this one.