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Full Version: Mix and match parts between HP-41CV and HP-41CX
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I have an HP-41CV in very good condition. Can I borrow parts from that and replace the ones on the CX with corrosion and possible corrosion of other parts? Both work currently. Should I not bother and wait until the CX fails?

This depends on whether the machines are Fullnut or Halfnut.

If one is a fullnut and the other a halfnut, then AFAIK the only common parts are the battery holder and I/O assembly (the flexible PCB on the plastic frame that connects to the battery pack, modules, etc).

If both are fullnuts, then the CPU board is different between a CX and CV. Some of the chips might well be the same, though. The keyboard PCB, display module, all case parts (apart from labels!), I/O assembly, CPU board connector, etc are the same.

If both are halfnuts, then you have less you can interchange. The ROM is different, and that's part of the display hybrid on a halfnut. So unless you want to start dismantling the heat-staked keyboard, the only things you can swap are the back case and I/O assembly. There's a bridge board in the CX only which contains the extended functions ROM, timer ROM, timer chip, extended memory, etc, but if you fit this to a CV all you get is the timer functions. The CV ROM will not detect the extended functions ROM.