HP 21 not powering on - repair/troubleshooting advice

[Steve Simpkin]

(01-28-2021 12:17 AM)dmh Wrote:  

(01-27-2021 06:02 AM)Steve Simpkin Wrote:  For the one with a non functional key, there is a small hole on the keyboard circuit board under each key. Take a stranded small gauge wire and spread the individual wires to make a fine wire brush. Using this and a small amount of contact cleaner, insert one of the wire strands into the hole behind the malfunctioning key and work it around to clean the key contact.

I don't have any contact cleaner but tried this with just the wire strands and now the '4' key basically works - thanks :-).

It doesn't register every time so can I use anything else around the house like vinegar?

Perhaps a tiny bit of alcohol.