I am now at the point where the disk controller is passing the RAM test but is hitting another fatal error. The Manual says there is a problem seeking to track 0 and I should replace the defective drive.
Take a look inside.
When I unscrew the rear cover on the bottom disk drive I am greeted with this image..
There is nothing so obvious looking in to the top drive but on removing the drive I get a similar story.
You can clearly see that both drive belts have fallen off their respective pulleys.
So what has happened is that the belt have lost their condition over the thirty or so years that they’ve been on the drives and just don’t grip any more.
What to do next?
Snipping through one of the belts and measuring gives a length of 588mm and so a diameter of 558/pi which equals 188mm.
Record deck belts are available around that diameter and I have one on order but the suggestions on-line say they aren’t a good option as they tend to be stretchy.
I have also found a flat industrial belt at 590mm length and so I’ve ordered a couple of those.
I’ll let you know how I got on.