Spent a day working cartridge mods yesterday. The two cartridges that came with the new used printer got converted to B2B cartridges but the filament kept snapping. Basically, old filament (PLA) in a B2B cart is a pain because you cannot re-thread it without taking the cart cover off. They do work well as external spools, though. As long as you know that the filament will break sometime during the night.

But that not the reason for this post. I was a bit surprised when the cart, which is at 98% of an original NG spool, failed to read the chip. Push on the cart and fine, it shows up, but not reliably. I've seen this before with printed hubs but never on a stock cart case. Even the pads on the chip look clean and new!

Well, the fix is easy enough. It is an old-school trick that I wanted to be sure to post here... pencil erasers! Basically, you get oxides on contacts and these may be non-conductive (most oxides are non-conductive but not all). Basically, just 'erase' the oxides from the gold contacts (transferred) and the chip's pads and all should be restored to near-new.

Happy Printing.