[GreenKeys] ASR 33 with strange symptom

[B Degnan]

Hi all - A while back I wrote about an ASR33 with a printer issue and I am still working to resolve.  The symptom is that 5th and the 8th "channel" are always punched or printed, vs. what was intended to be typed).  When I punch two papertapes from one good teletype and the problem teletype, I can overlay the tapes to see what's happening.  A tape of each key on the keyboard in succession (QWERTY...) shows the effect.  

I can use a screwdriver to hold in place to "block" the associated 5th bar that is misfiring and in doing so I can get the linefeed character to print / punch correctly.  That trick does not fix all problems though.

It appears that what's sent to the printer is the same incorrect codes.
I have carefully removed the printer from the chassis to inspect the underside of the printer.  I have compared and contrasted with a working teletype.  I did not see any obviously misaligned springs or bars.  It's a pretty clean machine too.  I have swapped the UCC-6's with no effect.   I have verified mykeyboard against the photos Wayne sent me to verify that the keyboard was ok - At least the thin metal pins are all in line.  I have disconnected the reader to eliminate this variable.
I read the suggestions from the last time I asked about this machine but none lead to a solution.  There could be a weak spring or a stuck metal bar or a code bar out of place I did not notice.  Not easy.

I recognize that I will need to continue to drill down into the machine and as I have time I will keep working on it on this end, but I thought I'd at least report my progress because I got a few replies to my initial inquiry this past summer.  If there a spot on the teletype that I could photograph to help one of you help me diagnose the cause of this problem I would be happy to post them someplace.
Thanks and best wishes.

Bill Degnankennettclassic.com
Kennett Square, PA




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