Teletype Troubleshooting

Bruce Lane kyrrin at bluefeathertech.com
Sat Apr 30 01:16:29 CDT 2005


	I used to service these machines for Western Union years ago.

*********** REPLY SEPARATOR  ***********

On 28-Apr-05 at 21:27 Bill Kotaska wrote:

>I am looking for troubleshooting tips for a 33 teletype.
>
>I'm testing in local mode and am getting incorrect characters 
>on (almost) every keypress. The characters will change even 
>with repeated pressings of the same key. I am pretty sure the 
>keyboard is outputting the correct codes.

	Never assume. One problem area we had was that the stiff spring-contact wires that the keyboard uses to set up the code can get dirty or oxidized where they contact the common busbar. Check this. Also, check the wiring between the keyboard and the distributor plate.

>I wiped down the distributor surface (it was pretty grimy) and no change.
>I tried adjusting the range finder but could never find a point where the 
>characters were consistent.

	Did you change the carbon brushes in the distributor rotor? That was another problem area for us.

>Is it possible to disconnect the motor drive belt and rotate the shaft 
>manually to get a closer look at what is happening mechanically?
>It's very hard to see what is going on in the selector area with the
>shaft spinning so fast.

	Absolutely it's possible. That's how we troubleshot a lot of problems.

	I would, however, strongly recommend that you try to get a service manual for this beast. It came in a three-volume set.

	Happy tweaking.



-=-=-=-=-=-=-=-=-=-=-=-
Bruce Lane, Owner & Head Hardware Heavy,
Blue Feather Technologies -- http://www.bluefeathertech.com
kyrrin (at) bluefeathertech do/t c=o=m
"If Salvador Dali had owned a computer, would it have been equipped with surreal ports?"





More information about the cctalk mailing list