Switch the heads around and make sure they are connected to the circuit board assembly securely. If the problem follows them, I am afraid to say those heads are dead. This happened to me twice in the last 6 months (purchased 4 heads in 6 months). After staying on the phone with the tech both times for over an hour and trying various fixes, nothing helped. In my case I attributed it to the wiper assembly having so much build up it was not leaving the print head clean and allowed air in to the capping station which will dry up a head. I actually remove my capping stations when I clean them instead of just using the swabs, the last 5 years of ownership I never once wiped down the wiper assembly (lesson learned). I check and clean it religiously now. My day job requires that I travel from time to time. In 2014, I filled the white lines with maintenance fluid and deployed to Iraq for 6 months, returned and started making t-shirts. Fast forward to 2017 and I leave for 4 and 3weeks at a time, I prepare the lines as usual but this time there is so much white ink built up on the wiper assembly its not getting a good swipe and the capping station is not sealing correctly which lets air in.....dead on arrival both times. I finally figured out how to correctly clean the wipers and I hit that little head cleaner button daily just for the heck of it. Does it waste ink? Sure, but I would rather blow a little ink than have to buy another print head. Oh and the Image Armor B-series inks are out now......I have them but have not loaded them, I still have a white cartridge of the brother left to burn through before I load them.