Testing repaired HP41C

I have received today a fantastic tool for testing the HP41c/cv/cx calculators that I usually repair: clones of the HP service modules. 

HP released two versions of the service modules: one for HP41c and another for HP41cv/cx machines. You can read the details from the service manual:

HP41c Service manual

These modules greatly simplify testing, including memory, screen, keyboard, status, etc. We will discuss these modules and other diagnostic tools in further blog issues.