On Sat, Jul 17, 2021 at 2:28 PM johnr@grebnesor via cctalk <cctalk@classiccmp.org> wrote: > > Hello, > > I came across a web article in which you discussed restoring an HP2100A. I > spent many years working on this computer and have the front panel. I am > doing some work on it to produce a display for fun. I am replacing the > incandescent globes with LEDs and using a Raspberry Pi to control them. > > The question I have is, do you know an easy way to remove and insert globes > in the front panel switches please?
The HP 2100A front panel uses T-1.75 Bi-Pin base miniature lamps. The last time I replaced some, if I remember correctly, I used Chicago Miniature CM7361 lamps for replacement. I forget if I was able to get a grip on them at all with needle-nose pliers to pull them out, or if I used something else. If you look for purpose built tools it appears that there are a couple of common styles. One style uses some sort of flexible plastic or rubber tube that is just the right diameter and wall thickness that it can be pushed on to the lamp, and then maintain enough friction on the lamp to pull it out when the tube is pulled out. Another style uses a metal tube that is split along its length that can be pushed on to the lamp when the halves of the tube are separated, then the halves of the tube can be pressed together to grip the lamp so it can be pulled out when the tube is pulled out. An example of the second style that shows up in a lot of lamp extractor searches is the Jonard S-339: https://jonard.com/s-339-lamp-extractor At somewhere around $30 for those tools I haven't been curious enough about buying one to see if it is suitable for removing and inserting HP 2100A front panel lamps.