Cartridge misfit?

I have a 700ml cartridge for VLM that I used for years (2011-2016) in a 7900. I traded the (dead) 7900 for a (dead) 9900 last year. Since it was dead, I didn’t get around to working on it until last month. At that point, the VLM didn’t register in the 9900 - it doesn’t think there’s a cart in the slot. Since it had worked for years, I assumed that the chip had gone on the fritz. Well, the new chip came, I installed it - and no luck. The printer still doesn’t see anything in that channel.

So I put my Piezoflush cart for that channel in - success. An old - very empty - Epson 350ml cart also registers, albeit empty. So I think the printer is probably fine.

What else should I check on the failing 700ml cart with either original or replaced chip? I don’t like the chances of both the old and new chip being non-functional, so I am inclined to think that there’s something goofy with the cart itself. Of course I can’t realistically check the clearances and contact point of the cart while it’s in the printer.

This definitely isn’t a life-or-death situation. This 9900 is about to be converted to Piezography and the only reason for putting an ink-ful VLM in this printer at all is to verify that the channel is clear, which it has been all along aside from the usual not-used-in-months clogs.

The indent where the chip is may be a bit old.

Do this. Put the (new) chip on. Make sure it’s perfectly parallel to the cartridge (no sloppiness side to side) and make sure it’s stuck against to front (ink outlet end) of it’s base.

Then take some clear tape and tape the bottom half of the chip securely to the cartridge. This ensures that the chip will not slide back when you put the cartridge in the printer.

This should do the trick.