HP-65, 45, 80 On/Off Switch Problems

[rprosperi]

The simplest thing to try is to just put a drop or two of DeOxit (Red) into the power-switch slot and work it back and forth gently 10-20 times (remove batteries while cleaning). Most likely, this will clean the contacts inside and the switch behavior will return to normal.

If so, then it is good to use something like Lubriplate DS-ES for long-term switch lubrication and contact health (though this latter action might be something you leave to the buyer, as he/she can decide if they want to open the case to this the "right" way).

https://www.amazon.com/CAIG-Laboratories...B0002BBVN2