PPC ROM in HP-41CX

[ThomasCox46]

For almost two days the HP-41CX which had been dead for six months, came to life after removing the PPC ROM. But as of today the 41-CX is dead again. Removed all modules, checked batteries, nothing helped. What I thought was a restored 41-CX is now dead.

I took what I thought might be a defective PPC ROM and inserted it into a working HP-41CV where it showed up normally in the Catalog and functioned normally.

Any thoughts on how to once again resurrect my now dead HP-41CX?

Of course, the good news is that the PPC ROM is proven to be good.

[BillBee]

It could be a few things:

Common ones:

The ribbon strip is no longer making consistent contact with the main board.

-Corrosion, broken case back (where the top screws go through the plastic gets brittle with age and can break not allowing for contact pressure).

If its a full-nut 41 it could be a lower post or zebra strip issue.
-Corrosion, lower posts.

A search of this site will bring you a wealth of suggestions.

-Bill