HP 25 Flaky Power Switch

[oldRPNlover]

I have an HP25 which served me well back on college (a long time ago). It is in good condition with no corrosion on battery tabs. I replaced the batteries out of caution since the ones in there were from 2005. It appears as though the power switch is flaky because it comes up with various digits (0s) upon start up. Usually the first two digits light correctly. Sometimes I get all the LEDS on (0s), and sometimes a few zeros and some decimals, and just about any combination imaginable. If I wiggle the switch, the display changes.

The batteries are charged well and seemingly making good contact.

I have it apart but see no way to clean that switch and the keyboard does not come apart. I hate to spray anything but air in there.

Thanks for any insight!