🚀 go-pugleaf

Help, I am at my wits end!  I have a Powermac 8100/100 at work, which 
until late last year was very reliable with very few crashes, running sys 
7.5.1.  When I upgraded to 7.5.3 it was still quite reliable but would crash 
periodically in a weird fashion.  At the top extreme left of the screen 
illuminated area (where the edge of the display curves)  a short single 
pixel high line of shimmering coloured pixels would appear at the moment 
of crash and from then on no input from mouse or keybourd has any effect.  
Only cmd-ctrl-power to force restart.  after the restart all used to appear 
normal.  As this only happened infrequently I put up with it (as you do!).  
In the press I read that 7.5.3 was a bit buggy and opted to go up to 7.5.5 as 
this was reported to fix quite a few causes of instability.  The frequency of 
crashes was still tolerable but always the same sort of crash was the only 
sort I got.

Nonetheless I persevered and then upgraded to 7.6.1 and the problems 
began for real.  Running the 7.6 installer, everything went well until the 
installer decided it could not continue "because of an error".  Of course 
instead of leaving the disk untouched it had screwed up the previous system 
folder.  A reboot brought the dreaded chimes and sad mac.  Fortunately I 
have two external disks attached, one with a bootable system on it, so I 
rebooted off the external and deleted the screwed up system folder and 
restored from a backup.  I still wanted to get to 7.6.1, so I (foolishly) had 
another go and the end result was the same.

Getting fed up I did an identical process at home on a 7100 with absolutely 
no bother at all.  So I thought "I'll do a clean install of 7.5.1, perform the 
upgrades on the new unused system folder all the way to 7.6.1" - cos 
something must be wrong with my present old 7.5.5.

Now a Power mac can bot of its install CD, so I did just that, wiped the olde 
system out and started a clean install - of 7.5.1!  The mac went roughly to 
the point where it says it cannot continue due to an error, and leaves the 
disk untouched (well it left a system folder with most of teh necessary 
files for 7.5.1 on the disk - so it lied a bit)

To cut a long story short, I eventuall managed to get the machine to run 
with 7.6.1 and it went well for a while.  Then these same crashes came 
back, only much more frequently, still with no identifiable cause - it could 
be mid print, mid-save, mid file open, using any application, just any old 
time - very annoying.

I cannot get a clean install to work from my original system 7.5.1 CD, nor 
an exact duplicate fom a different source.  When I restore from a backup I 
still get these crashes, I've reformatted the drive several times now all to 
no avail.

Why might my mac refuse to properly install a virginal operating system 
from the same CD it used to install from.  Norton says the disk is fine, disk 
first aid says the same, yet I cannot install any operating systems.  I can 
restore old copies of operating systems which then work OK but with 
crashes.

Any input at all would be appreciated (apart from any PC users who might 
say "get rid of it" - that I don't want to do)

Steve Parker
steve@parkfish.demon.co.uk