Shareware Grab Bag/Shareware Grab Bag.iso/090/tandon.fqx/TANDON.FIX

Text File | 1984-12-03 | 6KB | 92 lines

THE ABSOLUTELY UNAUTHORIZED GUIDE TO TANDON DRIVE REPAIR
                     by David Welcher

Before you drive yourself crazy, peek under your "original equipment"
disk drive with the IBM label on the front bezel, and make sure it
says Tandon and not something else, like C.D.C., for instance.  Otherwise
what follows may not make complete sense.
ONE KEY RULE:  Never tinker with anything still under the warranty!!
Now let's begin:
The problem:  Tandon drives (they are often marked IBM on the front
of the bezel) have a plastic stepper motor guide which rides on
twin polished metal rails at the rear of the drive.  This "reads"
the open slot on the diskette.  As the drive ages, friction and
dirt--including stray oxide particles--gum up the rails.  Sooner or
later, the drive will make a grating, vibrating noise and keep giving
the error message:  DISK ERROR.  Today, mine did just that.
A survey of local repair services turned up these options:
IBM:  $110 per hour, minimum 2 hours  (a NEW drive would be cheaper)
XEROX:  Bring in the WHOLE machine, and they will get it back to me
        in four or five business days.  No price given.  A secretary
        kept acting as interpreter, and would not let me talk to a
        technician.  (They are at Lexington and 43rd St.)
SORBUS: I spoke to the Westbury office.  EXTREMELY helpful and very
        friendly.  I could swap for a rebuilt drive with a 30-day
        guarantee on an "over-the-counter" basis.  Cost:  $180.
47th ST.:  New CDC, Tandon and half-height Teac drives available, in
           stock, for immediate delivery, ranging in price from about
           $160 to about $200.  NOTE:  Knowledgable, friendly store
           with good prices on everything.

WHAT YOU NEED TO FIX YOUR TANDON DRIVE:
                 1:  Small flat-tipped and phillips screw drivers.
                 2:  Small, clean, LINT-FREE rags.
                 3:  Precision instrument oil--can be obtained from
                     a jeweler (watch oil) or stereo store (used to
                     oil direct-drive turntable bearings.
                 4:  PATIENCE!!  You can't rush this job.

WHAT I LEARNED:  With nothing to lose, since I was going to buy a new
drive anyway, I disassembled my unit.  Take it out of the CPU by
removing two side screws, at right for B: drive, at left for A: drive.
Remove the very wide ribbon cable at right rear--unplug gently.
Remove the VERTICAL white plastic plug at left rear (as you face the
front of the computer).  This is marked #10 or #11.  Pry it apart very
gently--the lower half plugs into the inside of the upper half.  Do
not try to remove the upper half from the drive itself.  Do this
VERY SLOWLY.  Slide the drive out through the slot in front, being
EXTRA CAUTIOUS not to hit any of the electronic components against
the frame as you slide it out.  Make sure there is a BLANK disk in the
drive before you slide it out.  The disk protects the read-write heads.
Use a blank to avoid accidentally ruining any data.  After the drive is
out, place it on a flat surface on a thick newspaper to protect from
damage.  Remove the two top screws, one at each side.  Slide the circuit
card free of the notches and fold back safely out of the way.  The
black plastic assembly you see is the stepper guide.  Make sure the
drive door is closed.  Put some alcohol on a lint-free cloth and rub
down the twin round rails.  Make sure the rag is barely damp.  Move the
black stepper assembly forward and back, and wipe all parts of the
rails.  DO NOT DRIP!  Now take a small bottle of wrist watch or other
precision equipment oil--I use the tube supplied to oil the bearing
on my stereo turntable.  Place just two drops on each rail, in the zone
covered by the movement of the plastic guides.  This will be at a
different point on each rail.  Reach down at the right of the stepper
and observe that a motor shaft turns a cam as the stepper is moved in
and out.  At the forward-most position the cam has a notch.  Place
just two small drops in this notch and on the cam.  Place one more drop
on the end of the motor shaft at the other side of the motor.  Reach
into the cavity as far as you can, but make sure that you put the oil
on the shaft and not in the air.  Now cap the oil and place it far
away from the drive.  Work the stepper forward and back, slowly at first
and a bit more quickly later.  Wipe any excess oil off with a dry,
lint-free rag.  If any more black stuff appears on the metal shafts,
wipe it away with a clean, LINT-FREE rag.  When fully clean, run your
clean finger over the rails to smooth out the coat of oil and remove
any buildup.  If you can SEE ANY OIL AT ALL, except for a slight shine,
which is O.K., wipe some more.  When you are done, there should be no
visible residue and the stepper should slide smoothly.  Re-install the
two top screws.  Very gently slide the unit back into the frame, again
watching out not to hit any of the top electronic components against
the frame.  Re-connect the small white cable at the rear (#10 or #11).
Re-connect the large, wide ribbon cable and make sure it is not pinched.
Re-install the two side screws which hold the drive in place.  Connect
the monitor, keyboard and cpu to electric power.  Place DOS disk in
A: drive and a disk with SOMETHING ON IT in B: drive.  I hope your test
is as successful as mine was.  Congratulations on having just saved
yourself $200!
THE PROCEDURES OUTLINED HERE ARE PRESENTED FOR INFORMATI/84 22:49   PROOFIBM.BAS   5916     11/04/84 20:36
RENTAL  .WKS   4736   A 01/08/84 01:49   PCT500  .BQS  46592     10/03/84 16:28
SPEEDKEY.COM    512   A 01/08/84 01:14   NEWTRON .BAS   3456     10/04/84 10:19
SPEEDUP .COM    128   A 01/08/84 01:53   PROOFER .BAS   2173     11/04/84 20:56
SPEEDUP .DOC    512   A 01/08/84 01:53   MENU    .BAS   5120     10/04/84 10:30
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