HP85a with a few intermittent keys - looking for refurb advice.

[Juror22]

I have an HP85a that is in pretty nice shape (I'm aware of the drive capstan issues that older tape drives have, but that is for another day). I'd like to know if anyone knows the proper method for taking apart keys on the keyboard and refreshing them. I've got a few keys that sometimes work fine, then won't, then they will again. I suspect some cleaning is needed, but I don't want to destroy the keys taking them apart incorrectly, to find out.

Does anyone know how?

 

[cruff]

You can scavenge key parts from some of the old TI-99/4 home computers, and possibly other keyboards from that time frame. The key caps can be removed by pulling them straight out. The thin walled square piece the keycap plunger fits into often splits causing the sticking.

 

[Juror22]

...The key caps can be removed by pulling them straight out.

That was exactly the information that I was looking for, I pulled the keys with a chip puller, was able to clean them up and both are now working perfectly. Its an interesting mechanism - I had no idea the TI-99/4a's were like that (it looks like a tiny pair of gold ice tongs inside). Now I'll have to go dig out my TI's and check their keys out too.

Thanks for the help! And also for the quick response.

 

[legalize]

You may also find some of the videos on AkBKukU's repair playlist useful as he did 3D printed stems for his HP86.