hp-21 key malfunction

[Marc Pepin]

The battery pack leaked in my hp-21.I've clean the calculator put new batteries in.The calculator works well
when I test it outside the beige casing, but when I put all
the thing together the blue, rcl and clx key don't work.
(The battery pack fit real tight in the casing. It seems wider a bit because i've pry the old batteries out.)
Hope someone has a clue on this.
Thank you
Marc Pépin

[Phil]

Hi Marc,
try a cleaning with printed board solder flux cleaner like
Electrolube "Flux Clean" or contact cleaner like Chemitronics "Pow-R-Wash" without warranty.
Fortunatly, if it's ok afeter cleaning, protect the contacts with Electrolube "contact Grease" and remove all Nicad battery when calculator is not used
Regards.
Philippe