Quick checks when you bring home a filthy Model 28.
Don't turn on the motor until you are sure that nothing is binding and that you have cleaned and lubricated everything!
My videos are as crude and dirty as this teletype. I probably left out some things and/or made errors, but I've written down this procedure for 3 or 4 folks and figured videos might help.
keyboard/base - make sure the keyboard drive shaft turns and the code levers and transmitter work. And check that the motor turns!
typing unit - make sure that the main shaft turns and that the typebox moves OK.
complete unit - make sure that the motor, typing unit, and keyboard all mesh and cycle.
low low speed checkout - hook up a loop supply and turn the motor by hand to type and print characters in very very slow motion. Verify that your keyboard transmitter is operating properly and that your typing unit's selector is operating properly.
Don't turn on the motor until you are sure that nothing is binding and that you have cleaned and lubricated everything!
Good Luck and Have Fun,
Nick K4NYW