Just for future reference regarding iRC5180/iRC3200 series drum units.
If you turn AINR to "1" BEFORE you fit a drum then the fuse will not blow.
It's in COPIER/FUNCTION/INSTALL.
This is the best way to test a new drum and a machine that you suspect is having issues that you believe are being caused by the drum without having the drum count reset.
You'll be able to still write the new unit off as such.

I think that was what Screwy was referring to?