Cartridge puzzle

[duncan22]

Have been refilling cartridges with no problems for some time with no problems but on refilling an original Canon CLI -8C which I have refilled and used about 5 times a nozzle check showed no output.
Replaced with another cartridge and everything is ok, so that rules out the printer.
The cartridge has been reset with no flashing light or error message showing. The air hole has not been blocked in any way and was refilled in the usual manner using the well known german method.
The sponge does not appear to be over saturated and the base of the sponge which rests on the printer head is wet with ink. No ink is dripping out of the cartridge.
None of this is a problem as I have had more than my moneys worth out of it but I was just curious as to what could cause this.

Thanks

 

[stratman]

A cartridge's sponge can become stiff and not allow for smooth flow of ink. The reasons are varied and hypothesized - bacteria, fungus, problem with the refill ink, a sponge with little ink in it exposed to air over long periods of time, etc. A flushing of the cartridge may resolve the issue completely. Search on the forum for cartridge flushing for the myriad methods people have used. Grandad35 seems to have officially kicked off this topic with his thread found at http://www.nifty-stuff.com/forum/viewtopic.php?id=311. There have been other threads since.