The $5.00 Clock Fix

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           The $5.00 A4000 Clock Fix (A Tale of Joy and Sorrow)
   By: Craig Nori                                           cnori@usa.net
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I recently discovered that the clock on my A4000/030 was failing to keep
accurate time.  The following is the fix I came up with in order to correct
this situation.  BE WARNED!!  THIS FIX REQUIRES THAT THE SYSTEM BOARD BE
REMOVED AND SOME SOLDERING BE DONE ON THE BOARD.  NO WARRANTY IS IMPLIED OR
GIVEN AND ALL RESPONSIBILITY FOR THE USE OF THIS FIX IS UP TO THE OWNER OF
THE BOARD.  IF YOU ARE NOT COMFORTABLE WITH THE USE OF A SOLDERING IRON,
DON'T EVEN THINK OF ATTEMPTING THIS FIX!!!  ALL RESPONSIBILITY IS LEFT TO
THE READER!!!!  ANY REMAINING WARRANTY FROM THE MANUFACTURER WILL MOST
CERTAINLY BE NULL AND VOID.  IN OTHER WORDS, IF YOU MESS UP YOUR MACHINE,
IT IS NO ONES FAULT, OR RESPONSIBILITY, BUT YOUR OWN.  If that hasn't
discouraged you so far, perhaps my experience with this fix will.  But more
on that later.

After pulling the top cover off, I got my trusty multimeter out and
discovered that the lithium battery, BT176, was dead.  I decided that
replacing the dead battery with the same type would only result in my
having to do the replacement again at a later date as the battery wore
down.  A better solution, I thought, would be to install a battery holder
for easy battery replacement.  The first step was to get the old battery
out in order to find a suitable replacement.  Understand that the following
steps assume two things.  First, you are going to use proper ESD protection
in doing this fix.  (If you don't know what ESD protection is, should you
be doing this fix?  Probably not.) And second, my 4000 doesn't have a
processor card plugged into the system board.  The 68030 chip is on the
system board so you might have to remove the processor card as well, at the
appropriate time.  This fix involves the following steps:

1. Remove the top cover.
2. Inspect for battery BT176. It is a silver coin shaped thing on
   the left edge of the system board just ahead of the mouse and
   joystick ports. Etched in the top is a big + (plus) sign and 3V
   meaning a 3 volt battery. If you can't find it as described,
   put the cover back on because these directions do not apply.
3. Remove the internal hard drive and cable.
4. Remove all Zorro cards.
5. Remove the riser frame. This is the strip of metal holding the
   riser card down. There are two screws, one at the front and back.
   NOTE the slots on the frame where it rests on the riser card.
6. Remove the riser card.
7. Remove the front panel.
8. Remove the front drive bay and cables.
9. Unplug any remaining cables from the system board.
10.Remove the 9 screws holding down the system board and remove it.
11.Get out your solder sucker and remove the battery from the system
   board. There are 3 connecting points.

After completing the disassembly, with the battery in hand, I headed down
to the nearest Radio Shack and found a coin type battery holder and new
battery for my ailing Amiga.  The catalog numbers for the replacements are:

Cat# 270-430 Battery Holder
Cat# 230-162 3 Volt Coin Battery

The cost to me was right at $5.00 USD.  The new battery is physically
smaller than the old one, but not to worry, it works GREAT.  The legs of
the new battery holder aren't a perfect match, so I CAREFULLY bent and
formed the legs to match the fresh holes made by the old battery.  The
orientation of holder is the + pins along the left edge of the system
board.  I soldered the holder in place, slipped the new battery into the
holder, and reassembled my Amiga using the above removal instructions in
reverse.  The new holder looked like it was always meant to be there.  I
reset the time, powered off the system and waited about 15 minutes to power
back up.  When I did the time was correct and it looked like another
successful repair was completed.  My clock was working and I now could
easily replace the battery in the future.

A happy ending you say?  I thought so too until I realized that my speakers
were making a faint whistling noise and all the lights on my external modem
were on.  I tried to get some noise from my speakers by firing up Octamed
Player.  It started up, then the system crashed with a GURU.  Needless to
say, my heart sank into my shoes, and a little tear started to form.  I
couldn't think of anything I could have done to cause such a disaster.  In
a panic, I raced into the next room and tore through several of my Amiga
magazines, searching the ad's for a price on new CIA chips.  My mind tends
to multitask better when I panic and several thoughts were going at once. 
Should I attempt surface mount repairs on my own?  Straight soldering of
the chips or surface mount sockets?  Where could I send off my Amiga for
repair?  Could I live without my machine during the repair time?  My cries
of agony caught my wife's attention.  After explaining to her what had
happened, she suggested that I take a deep breath, drink a beer, and walk
away for a bit.  Good advice, I thought, but then she is smarter than I am.

I took that deep breath and cracked a cold one.  Sitting and drinking, the
events of the project started stepping through my mind.  One thing I did
mentally note, as I was disassembling my machine, was that some of the
system board mounting screws were loose as I was removing them.  The plan
was to make sure that they were all tight during the re-assembly.  I wanted
to make sure they were, as this was important to the grounding of the
board.  And you know, the loose screws were in the same area as the CIA
chips.  My heart was working its way back up to knee level when I started
pulling everything back out of my Amiga.  When I got the system board back
out, I flipped it over and there it was.  On the land patterns near the CIA
chips was a small splotch of solder.  I carefully scraped it off and
crossed all fingers and toes as I put everything back together.  I powered
up and watched my modem.  One light on as normal, so far so good.  Starting
Octamed Player resulted in music coming out of my speakers.  In stereo!
Nothing was permanently damaged and it all worked out fine.

My theory is, that during the last days of Commodore, quality control was
not at a very high standard.  Perhaps the loosening of the system board
screws was an acceptable fix for a sloppy soldering job.  And my tightening
of the screws caused the solder to short the CIA lines.  At least that's my
story and I'm sticking to it.  Hardware hacking can be fun and rewarding. 
It can also be disaster and heartbreak.  Or in the case of this project,
BOTH.  Which brings me to the moral of this rather long tale: BE CAREFUL
and DON'T PANIC!  And if you must panic, as in my case, remember to step
away for awhile if things don't go right.  Lastly, BE CAREFUL.  Did I
mention you should BE CAREFUL? 

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