HP-19C issue

[Giovanni Jimenez]

What could e the reason for this behavior on a HP-19C ?

"...When it is plugged in and turned on, the numbers continue to flash/scroll as if it is calculating a formula. All of the characters light up..."

thanks !

[Michael Meyer]

Hard to say for sure, but my bet is that there's a "fried" ACT chip. Or soon to be fried, if you plug it in without a good working battery. The 19C is essentially a Woodstock and prone to the same damage if plugged in without a good battery with good contact. Try powering it with battery or a power supply connected the to battery contacts only.