Chosen Solution
Battery store installed too powerful a battery (somehow same size as N type so fit} in HP 41CV and it never worked again with N Type. Person said it was “fried” and gave a different model replacement. Is it possible to fix or is it permanently damaged from overload.
Hi, It may be possible to fix it but looking at the start of the troubleshooting section in the service manual, you will need an ET-11966 service rom module and a port extender to start performing the tests to know what may be the problem. I can’t find either online, you may have better luck
