Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!rochester!pt.cs.cmu.edu!andrew.cmu.edu!cb29+
From: cb29+@andrew.cmu.edu (Chad Kavanaugh Bisk)
Newsgroups: comp.sys.amiga
Subject: A500 Hardware Problem
Message-ID: <oYd4cDy00W0K0Axkp6@andrew.cmu.edu>
Date: 25 Jun 89 02:57:19 GMT
Organization: Class of '90, Carnegie Mellon, Pittsburgh, PA
Lines: 62

Fellow Amiga Users,

	I recently ran into a problem which I am hoping has a very simple
solution.  My Amiga 500 has started to act very weird and is becoming
unusable, and I am hoping that someone can tell me why.  First off, my
current configuration is:

Amiga 500 with rev 5 motherboard (Serial Number ~5000)
Amiga 1080 color monitor
Supra 501 memory expander and clock
Supra external SCSI interface w/ autoboot ROMs
Supra 45 Megabyte hard disk (Miniscribe disk and controller)
Kickstart 1.3 in ROM
AmigaDOS 1.3

	I recently bought the hard drive, controller, 1.3 ROMs, and extra
memory from Lightspeed Distribution and installed everything over the
weekend.  Installing the ROMs was the hardest part, requiring me to open
the plastic case, remove the keyboard and the metal RF shielding, pull
the old ROM and put in the new, and put it all back together.  The hard
drive was pre-formatted and autobooted the first time I turned it on.  I
was having a ball that night setting up my personal directory tree.

	For one day everything worked fine.  The next day I had been using the
A500 fine in the morning.  I came back in the afternoon and the
freakiness started.  Everything autobooted fine and the workbench came
up.  Upon looking closely, I noticed that there was some extra garbage
on the screen that was shadowing the disk icons.  Some experimentation
revealed that any vertical line and some other lines had a duplicate
line drawn to one side or the other (it varied) at a varying distance.

	I broke the system down, removing the 501 card and the hard drive and
interface.  The problem was still there.  Now I noticed that the "Insert
Workbench" screen was totally screwed.  About every inch across the
screen, horizontally, there was a vertical line from top to bottom and
the hand/disk icon had several shadows.  These were not just screen
shadow images, but were actually written in to graphics memory.  The
flood fill blue of the disk picture was restricted to the left tenth of
the disk icon since it was blocked by one of the vertical lines.  This
resulted in a very scary looking boot screen (almost all black and
white).

	However, the Amiga still booted normally from either floppy or hard
drive.  I even played Hex to sooth my nerves for a while.  I love the
music that it plays.  I was listening to the intro music when the second
weird thing started.  The sound cut down to about 1/3 the normal volume.
 Further experimentation with other sound programs yielded a very
reduced volume and occasional static bursts.  I began to suspect a short.

	I opened up the Amiga and blew it out.  I checked all the free wiring
(capacitor and transistor leads) and the internal and side expansion
connectors.  Nothing obvious was found.  I then powered up with the
cover and shielding off and felt around for overheating chips or
components.  No luck.  I put it back together and cursed Commodore
hardware quality for a while.  Then I left to ask for help from my
fellow NetLanders to see if there was an obvious solution that I might
be missing.  My only recourse is to go to a local Authorized Commodore
Repair place and pay some hefty repair bills that I'd rather not have to
pay.

			-- Chad Bisk
			-- cb29@andrew.cmu.edu