Anybody has any ideas with this nozzle check pattern? a few weeks back my yellow cartridge of my ip4500 dried out and my friend tried to print without noticing. After that the printer shut off. Only after refilling (German Durchstich refill method and using chip resetter) and a few days lapsed, I managed to get it on again. After that every nozzle check produce the same pattern. I have tried cleaning the nozzle with liquid glass cleaner(with ammonia content) and with running tap water, but all have failed to get a better nozzle check pattern. I read somewhere in the forum that this kind of pattern is caused by electronic issue not because of clogged nozzle. Anybody got any comments?