[HECnet] TK50 issues

[Hans Vlems]

I guess you meant iso-propanol, right?
Just in case someone runs to the chemist for a pint of the aldehyde, which is a lot more toxic than the alcohol.

Verzonden vanaf mijn BlackBerry 10-smartphone.
Van: Jerome H. Fine
Verzonden: woensdag 14 mei 2014 03:19
Aan: hecnet at Update.UU.SE
Beantwoorden: hecnet at Update.UU.SE
Onderwerp: Re: [HECnet] TK50 issues


>Cory Smelosky wrote:
Evening all, 

Got a nice haul of equipment today...aside from the TK50 issues and the smoking VT340 everything seems to be okay! 

However: 

                                                                             CARTRIDGE PRESENT 
                                                                             HEAD AT TRACK ZERO 
                                                                             POSITIONED AT BOT 
             TRK NUMBER                       00 
                                                                             LOGICAL TRACK NUMBER = 0. 
             PHYSICAL BLK#             0000 
                                                                             PHYSICAL BLOCK NUMBER = 0. 
             LOGICAL BLK#                   00 
                                                                             LOGICAL BLOCK NUMBER = 0. 
             TAPE POSITION         000EFB 
                                                                             TAPE POSITION = 3835. 
             DRIVE STATE                 035E 
             RD/WRT STATE               1937 
             OPERATION FLGS           0201 
             CNTRLR STATUS                 0C 
                                                                             DRIVE ERROR 
             DRIVE ERR CODE               93 
                                                                             AMPLITUDE ON HEAD 2 TOO LOW 

and an error about it being unable to find calibration track 2 on the second drive lead me to believe the drives may be faulty.   The leader isn't broken and I've reattached it to the arm on the one where it had come off. 

How would I do about cleaning one?   Are the drives bad and a cleaning wouldn't help? 

(Yes, I tried multiple cartridges)  
Over 95% of the time I had a "bad" TK50, it was because
the heads required cleaning.   After sitting around for more
than a decade, the TK50 tapes no longer leave the heads
very clean.   Cleaning the TK50 head is quite easy once the
drive has been removed from a drive bay and the 3 bolts
holding down the cover have been removed.   A smaller
screw driver can then remove the bolt holding the piece in
front of the head.   I use Q-tips and isoproponal.   The whole
procedure takes less than 5 minutes.   No alignment is required
if just the piece in front of the head is removed since it blots
back into exactly the same position.   Probably the rollers
should also be cleaned as well.   I usually had to clean the
heads every time the equivalent of a complete TK50 tape
was used.

If the TK50 drive is going to be used frequently, it is best
to leave the drive out of the drive bay. with the cover off.
However, be sure to keep the same power source from
the backplane.   While a hard disk drive seems to accept
a PC power supply as the power source, the TK50 seems
to require the same power source as the backplane which
is used to power the CPU and other boards.   If necessary,
use an extension for the 5v / 12v plug that the TK50 requires.
The normal 20 pin (??) cable for signals to the controller
board is usually long enough to stretch to some other
convenient location outside the drive bay.

Jerome Fine