When I switch on the calculator, sometimes it has a blank display, or a full line of periods. After a few minutes, all the display segments flicker. Sometimes, when I press a key, I get a single flickering "8.", but nothing else happens. Nothing actually works.
Could this be caused, or related, to the ACT chip? This has been known to be a problem in "Woodstock" (HP-21, HP-22, HP-27) calculators. Or is it something else?
I have been using two slightly-used alkaline AA cells for the battery - but not the AC adapter. (One was not included with this used calculator.) I don't think the extra (3.0 vs 2.5) voltage is causing any trouble.