Hammer time: fixing the printer on a vintage IBM 1401 mainframe

1 · Ken Shirriff · Dec. 10, 2018, 6:06 p.m.
The Computer History Museum has two operational IBM 1401 computers used for demos but one of the printers stopped working a few weeks ago. This blog post describes how the 1401 restoration team diagnosed and repaired the printer. After a lot of tricky debugging (as well as smoke coming out of the printer) we fixed a broken trace on a circuit board. (This printer repair might sound vaguely familiar because I wrote in September about an entirely different printer failure due to a failed transisto...