Date   : Wed, 15 Nov 2006 23:41:18 +0000
From   : astravan@... (Alex Taylor)
Subject: Excitement, disappointment. Capacitors.

Hello everybody

I've just got very excited as I seem to have repaired one of my Beebs! 
It was the one with the hardware scrolling fault. In Modes 0, 1 or 2, it 
was showing the bottom of the RAM on the screen, whenever the scrolling 
was in effect. I simply swapped ICs out with a dead Beeb motherboard, 
unfortunately the one that did the trick was the last on my list. It was 
  IC27.

I also repaired one of the floppy drives I got from Wales! There was a 
shorted capacitor on the motor board, and the 40/80 switch was missing. 
Now it's working perfectly, but it's extremely rusty on the outside.

However, the Beeb I repaired doesn't seem to like disks. It wouldn't 
read my games disk that works on the Master upstairs. For the disk 
title, it gives a divide sign and a white block. If I save a BASIC 
program to the disk, it appears in the directory, but only until I reset 
the machine. It also appears that the DFS ROM only shows up in *HELP 
/after/ I've typed *DISC. I'm not sure if it makes any difference, but 
it has NFS installed too.

Another note on capacitors: I've seen a few eBay listings and postings 
in this group, about exploding power supplies. Loads of my Beebs have 
'exploded' and work perfectly - the same happened to my Apple IIe. 
There's a filter capacitor that's prone to exploding violently if it's 
not been used for a long time, however I've found that it's not an 
essential component and the PSU will work fine without it. It's also 
quite cheap and easy to replace if required.

-- 
Alex Taylor