Sunday, 25 February 2018

VIC 20 Future proofing

I have recently been future proofing my VIC 20 and carrying out some modifications.   I have replaced all 8 electrolytic capacitors as these tend to dry up and fitted heatsinks to the Video Interface Chip (VIC) and Kernal ROM.  These chips are run hot and are prone to failure so it is sensible to install heatsinks to prolong their life.

I used my trusty Duratool Desoldering Station which makes the job an absolute doddle, compared to using a desoldering pump and solder wick.
  
I have also carried out a couple of modifications to improve the VIC Video, further details can be found here and a useful video on the matter can be found here.   I have done the following:

  1. I added a 220 µF capacitor across the +5V supply to the VIC chip. (I connected the cap between pin 40 of chip which is connected to one side the ferrite bead (FB11) and ground)
  2. I removed the ferrite bead (FB9) connected to Pin 2 and replaced it with a 270pF ceramic capacitor.

Hopefully this will improve the chances of my VIC 20 lasting for another 30 years.  I picked up the heaksinks from https://www.retroleum.co.uk/c64-repairs-and-mods

Before

After

















Heatsink fitted to the VIC chip
















VIC Video mods