[comp.os.vms] 8mm Exabyte tape home repair success

belonis@milton.acs.washington.edu (J.James Belonis II) (01/01/90)

8mm Exabyte tape drive home repair successful...

One of my Exabyte 8mm tape drives ate a Sony tape cartridge and would
not open even after powerdown and power up.
The tape had apparently ridden up over the tape head cylinder
instead of being wrapped around it properly.  This may have been caused by
badly loading the tape.  I had not quite pushed the door closed far
enough to latch, and the door started springing open again.  I reflexively
did not let the door completely open or check the condition of the tape
cartridge but pressed it closed and latched quickly.

The drive did not have 'warrantee voided if opened' seals on
it (my other one does)  so I decided to try to fix.
First I probed through slots with a hex wrench to untangle tape
partially successfully, but tape would still not eject.
I used TORX T-8 and T-9 screwdrivers to remove the special screws in
the top and was able to get at the mechanism of the tape drive
but still no luck removing the cartridge.
Finally found the latch outside on the left side
(white plastic finger about 1" up from the bottom and 2" in from the front
which holds two electrical contacts together when tape is fully inserted).
This latch is accessible without taking the drive apart.
The latch releases when this finger is pressed toward the front of the drive
(i.e. opening the electrical contacts it compresses).
The door mechanism is spring-driven, so no power need be applied;
the door opens by itself.
My drive mechanism was still mostly in the 'loaded' position, but when
I applied power, it self-tested and completed the 'eject' operations.

I even repaired the tape by cutting out the bad tape and using a
Beginning Of Tape (BOT) foil marker intended for 1/2" reel-to-reel tape
to splice (the mangled tape was right after the leader
so I only lost a foot or so of tape).  Normal SONY 8mm tape has silver foil BOT
to splice the clear leader to the magnetic tape.
This was much easier than I expected.

Running the tape drive with the top open was an education in sweet machinery.

J.James(Jim)Belonis II, U of Washington Physics Computer Cost Center Manager

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