I have a 5Si that is putting up a 79 error code. I was there two days ago and cleared it by powering off & on the printer and emptying the print que. Yesterday it returned....I was wondering if maybe this could be caused by an application or something they are trying to print ? Maybe a flakey network card..this printer has one of those older network cards with a BNC connector on the front. Bad formatter ? Anyone have any ideas of suggestions ? Thanks Murphy