Hi, I got asked to change a cartridge chip on an epson T7200, with refillable cartridges, I have no prior experience with these types of printers, and I never printed on this particular machine either. But I changed the cartridge chip for matte black, and I ended up concluding that it is not the problem, as I was told. At first insertion it did recognize the cartridge, but I restarted the printer so it started with the same error again. If I remove and reinsert the cartridge it goes back to "Ready" screen. But if I try to do a nozzle check the error pops up again most of the time. As far as I can see it reverts back to this error as soon as I hear some mechanic parts initializing in the cartridge area. But by some miracle it did two nozzle checks, the first one was very bad, specially at the matte black, so i suppose the machine was not properly taken care of, but even after the second one came out almost perfect the error persists the same way, with old chip or new chip and only at this cartridge. I made sure the cartridge is properly fixed, I carefully cleaned the contact pins even tho no sign of ink or whatever was on it. I'm currently without any other idea. Besides probably reinstalling firmware? But maybe the solution would be more simple then that. So any suggestions are much appreciated. Thank you very much!!