IF IT WORKS, DON'T TOUCH IT

Copyright Dr Alan Solomon (1986-1995)

One  of the best rules about computers (and life in general) is "if it
works, don't touch it".  A lot of  damage  is  done  to  cars  by  DIY
enthusiasm;   unless  you  know  exactly  what  you  are doing, don't
tinker.  But sooner or  later,  people  are  going  to  start  reading
articles  about "how to tune-up your own disk drives", or "how to mend
your computer when it breaks down".   Our  advice  is,  don't  do  it.
Especially,  don't  do  "preventative  maintenance", as any DP manager
will tell you  that  most  breakdowns  happen  immediately  after  the
engineers leaves.

But you read these enthusiastic little pieces by people who have "done
it themselves", especially in the motoring magazines - what follows is
dedicated  to anyone foolish enough to actually take their computer to
bits for no good reason.

DOING YOUR OWN COMPUTER MAINTENANCE

Now  that  the  price of a computer system has fallen so low, it seems
silly to pay some firm #200 for a fuzz-faced child to come and do your
annual  check-up.   Many people do their own car maintenance, and cars
are far more expensive and complicated than computers, and no-one  has
been  killed  yet  by  a computer hardware failure.  It makes a lot of
sense to Do-It-Yourself when it comes  to  computer  maintenance,  but
very little has been written on the subject.

First  a  disclaimer.   You  should  take  advice  about  whether  the
instructions that follow apply  to  your  computer,  as  some  of  the
procedures described below could be hazardous.

Before you give your  computer  its  annual  service,  get  everything
you'll  need  ready.  You'll need a Phillips-head screwdriver, a large
ordinary screwdriver, some cotton wool, a wire brush, and a few  other
tools,  depending  on what you find inside.  You'll also need a bucket
of hot soapy water.  Clear your kitchen table,  and  spread  newspaper
over  it,  otherwise  you  could  scratch  it.  You should also spread
newspaper on the floor, as otherwise, static  discharge  could  damage
some of the delicate circuitry.

Switch off the power, and unplug it at the mains to be doubly sure.  A
240  volt shock is rarely fatal, but there's no point in taking risks.
The first job is to remove the VDU and unplug the keyboard.   Work  on
the keyboard first, as it is fairly easy.  Remove all the keytops, and
the space bar, and wash them in hot soapy water.  A few  springs  will
jump  out  -  discard them, as they are just part of the packing, that
normally no-one bothers to remove.  Unscrew the back from the keyboard
(it's  held  on  by two Phillips screws) and wipe over the back with a
clean rag.  When you reassemble the keyboard,  you'll  find  that  the
space  bar  doesn't go back the same way it came off - you may have to
leave it off.  Don't worry, there's a button underneath  it  that  you
can use instead.

15000 VOLTS - IGNORE IT

Next, tackle the VDU.  Remove the back, switch on your  computer,  and
plug in the mains power.  Ignore the notices about 15000 volts, that's
just put there to frighten you.  Watch the screen as you reach  inside
and  feel  for  the  focus  adjuster;  VDU's need refocussing every so
often.  If you find any other knobs inside, you  could  try  twiddling
them  too;   it's  surprising  how  often a monitor can be improved by
proper adjustment.

The next job to tackle is the main one - the system  box.   The  black
back  is  held on to the grey case with five rivets.  Use your biggest
screwdriver to lever it off;  you might have to exert quite a  lot  of
force.   There  is  one rivet in each corner, and one in the middle at
the top.  Gently slide the grey case forward.  When it is nearly  off,
it  will  catch  on  something;   give it a good jerk and it will come
free.

SILENCING THE FAN - PERMANENTLY

Inside, you'll probably see an appalling mess of wires and  circuitry.
Don't worry, it's supposed to be like that.  At the back on the right,
you'll see a large box.  That's the power supply, and at the top of it
is  the  fan that makes all that noise.  It's easy to silence the fan,
though, and surprising that so many people  still  haven't  done  this
simple  job.   Take  an  ordinary  biro,  and remove the ink cartridge
inside.   Cut  off  the  metal  end  with  a  pair  of  scissors,  and
half-insert  the polythene tube that is left into the grill at the top
of the power supply.  Don't push it all the way in, but bend  down  to
top  half  of the tube, and Sellotape it to the power box.  You should
have no more fan noise.

Next, remove the upright boards by unscrewing the brackets and lifting
them.   They  get  very  dirty in use, and this could contaminate your
data if left untreated.  Use the wire brush vigorously on both  sides;
especially  on the back (where there are no components) you should try
to remove all the unsightly traces of copper that were  left  over  in
the  manufacturing  process.   The  slots  that  the  boards  fit into
probably need re-greasing;   use  only  the  finest  grease,  or  even
better,  use  butter  (but  it  must  be  unsalted,  or it could cause
corrosion).  The big board at the bottom is  called  the  motherboard.
If  you're  feeling  energetic, you could pull this out.  You lever up
the left side and pull the board out sideways.  If you do  remove  it,
it's a lot of hassle sliding it back in later, but it makes working on
it easier.

CLEANING THE GREASE OFF THE CHIPS

Prise  out  all  the  chips  that are socketed, making careful note of
where they came from.  Don't remove any of the chips that are soldered
in,  unless  you  are  willing to tackle the job of re-soldering them.
Wash the chips in hot soapy water, and rinse and dry  them  carefully.
Straighten  any  bent  legs by heating them with a soldering iron, and
while they are hot, use a pair of pliers.  Wire brush the motherboard,
and  make  it  nice and clean, again removing the coppery stuff on the
back.  Insert the chips back into the motherboard,  making  sure  that
they  go  back  into the correct sockets.  It doesn't matter which way
round they are, though, as modern components are self-orienting.  Once
everything  is back on the motherboard, you could give it a fresh coat
of paint, as the old paint is probably worn out, and paint is a  vital
factor in the fight against corrosion.

Inspect the expansion boards carefully.  If there are any loose chips,
you should tap them with a wooden mallet to make sure  that  they  are
fully  home.   Some  multifunction  boards have a battery to power the
on-board clock.  You should replace this with a similar  battery  that
you  can  get from Boots.  Most batteries are held in with a clip, but
some are soldered in.  If it is soldered in, all you need to do is cut
the  wires  to  get  it  out.   The  new battery can be out in by just
twisting the wires together.

WASHING THE FLOPPY DRIVE

Next,  you  can tackle the floppy disk drive.  Remove it by unscrewing
the two screws at each side, and gently pulling it forward.  A lot  of
dust and grit builds up inside the floppy drive, as it gets in through
the open drive door.  You should get as much of this off as  possible,
as  otherwise it could contaminate your disks.  Use a strong detergent
such as Flash, hot water and a loo brush to  get  into  the  crevices.
Rinse it, and dry it carefully using a hairdryer (or pop it into a hot
oven for a few minutes).  It's important to dry it  quickly,  or  else
parts  of  it could begin to form rust.  You should then lubricate the
moving parts;  3-in-1 bicycle oil is probably the best to use.

The  floppy drive is another annoying source of noise, and without the
fan, it will be very noticeable.  But if you look at  the  drive,  you
will  see  an  arm  that  slides up and down to read the disk.  If you
carefully pack  its  track  with  cotton  wool,  held  in  place  with
Sellotape, this should quieten it down a lot.

SCRAPING THE HARD DISK

Hard disks need a  lot  of  maintainance,  as  they  are  particularly
delicate.  If you are working on your kitchen table, you should try to
sweep away any crumbs or fluff, in case it gets in amongst your  data.
Remove  the  hard  disk from the computer by undoing the two screws on
each side that hold it in, then ease it gently forward.  On top of the
disk  is  a printed circuit board;  unclip it by levering it up with a
screwdriver.  Open up the drive itself (ignore the warning  about  not
opening it;  all components of a PC are meant to be user-serviceable).
When you have opened it fully, you'll see some  platters;   these  are
where the data is recorded.  But with constant use, a brownish deposit
builds up;  remove this with fine glass paper.  Emery will NOT do,  as
it  will  scratch  the surface, but if you can't get fine glass paper,
Ajax or some other pot-scourer will do just fine.  After the  surfaces
are  clean, wash them carefully in water (don't use soap, or they will
become sticky) to remove all traces of the cleaner.

THE PRINTER

Next the printer.  Printers are very easy  to  dismantle,  but  rather
tedious,  as  there are a lot of fiddly screws and springs.  Make sure
you have a handy box to put them in, as if they roll under  the  table
and  get  lost,  you  might  find  that  your  printer  misses the odd
character.  The main thing to watch out for in  printers  is  the  ink
roller.   If  that  gets  dry,  the printing gets harder and harder to
read, until eventually it is completely illegible.  You should  re-ink
the  roller,  using printers ink (which is particularly black;  get it
at any art-shop).  A pastry-brush is ideal for spreading it on evenly.
If  you  have  a  laser printer, there is a cartridge full of powdered
ink.  Do NOT fill this with liquid ink, as it will leak all  over  the
printer;   instead  use poster paint (again from an art-shop).  If you
want a change from boring black, use a  nice  bright  colour  such  as
orange  or  blue, but it you use yellow, you won't be able to print on
white paper, you'll have to use a contrasting paper.   Make  sure  you
rinse  out  all  the  black  powder  before  filling it with any other
colour.

At this point your computer has been thoroughly serviced,  and  should
be  in  a  totally  dismantled  state.  In the next issue, we'll cover
re-assembly, finding and fixing  any  minor  problems  that  may  have
cropped up, and where to buy a new computer.