+- HP Forums (https://www.hpmuseum.org/forum)
+-- Forum: HP Calculators (and very old HP Computers) (/forum-3.html)
+--- Forum: General Forum (/forum-4.html)
+--- Thread: HP-45 power switch missing (/thread-22725.html)
HP-45 power switch missing - gbever - 11-19-2024 12:49 AM
I am resurrecting my HP-45, which I bought in 1973. The power adapter had a bad 400 uF capacitor and maybe charging transistor--which I fixed. But my problem is that somewhere in past years the metal part of the power slide switch disappeared, so I've had to solder a wire jumper across traces to turn it on.
Does anyone know where I can obtain this metal slide? Or the whole power switch?
See the attached photo.
RE: HP-45 power switch missing - John Garza (3665) - 11-21-2024 12:47 AM
Most likely from a donor machine.
They were used on the Classic, Woodstock, and Spice series.
So the donor does not have to be another 45.
Buy a cheap 'for parts' machine and cannibalize it.
OTOH, you could try building one with a paperclip.
Ensure only the rounded metal touches the gold contacts on the PCB to prevent scratches.
-J
RE: HP-45 power switch missing - teenix - 11-21-2024 01:34 AM
I could send you one, but the postage is crazy.
You might be able to make one with some brass strip from a hobby outlet. Make sure the contact surfaces, especially at the sides of the metal, are nice and smooth, and give those same surfaces a rub over with some metal polish as well. The idea is to stop the contact material scratching its way into the circuit board contacts. I don't think you will have to split the contacts as original with the dual fingers on each end. The original switch material thickness is 0.01 inch.
Apply a tiny amount of switch lubricant when ready to reassemble.
cheers
Tony