R Jet 4 corrupt print

Having stripped and flushed the print head with IA cleaner and reassembling the printer I had a fantastic print, all nozzles firing etc. Wiped the print head face with a sponge swab and the left the printer in standby overnight.
When I now try to print I get a solid coloured bar printed across the whole t shirt and about a cm of the frame of the platen. The image itself is still printed in the correct place but the yellow and blue nozzles appear to be permanently firing regardless of what image is being printed. This also happens when trying to print white only. (white nozzles are firing )
I have attached an image of the print but have wiped the frame clean before hand. The small black outline box should be yellow with test inside.
The platen registers correctly on load and appears to move the platen to the correct postion for printing so there are no sensor issues.
I have also tried two different installs of Cadlink on different laptops
Any ideas before I start stripping this down again.
Cheers