My HP41CV just arrived. Cleaning tips?

[mfleming]

I haven't tried either method, but I've seen two approaches to cleaning the key contacts posted in the forums. The first involves swirling some DeoxIT contact cleaner around using a thin wire or bristle from a brush. There are plated thru holes in the main PCB behind each key where you can insert the wire or bristle. See this link for where you can buy the contact cleaner (highly recommended if you plan on doing any restoration).

http://store.caig.com/s.nl/it.A/id.2914/...ategory=20

Another method involves placing the bottom keyboard assembly in an ultrasonic tank with clean water. There was a long discussion somewhere on the inadvisability of using distilled water (do a search using the site:hpmuseum.org qualifier with you favorite search engine). The keys should be immersed but the display should remain dry. leave the keyboard & case to air dry a few days before reassembly. This method would dislodge any stray material that might have been lodged in the key contact dome.

Both methods do involve disassembling the HP-41 and removing the CPU daughter card and its contacts. With a calculator this old, you introduce the chance of a broken post, bad contact after reassembly, ESD damage and all sorts of problems. Don't be discouraged, just be careful! There are any number of posts detailing the process and maybe an article or two. Dig in and read up before opening the case.

~Mark