The captop has absolutely nothing to do with this problem. This is an electronic issue, not an ink flow issue. Based on the new info on the history of the problem, I would reassess my diagnosis to possibly being the printhead itself. Unless you are technically adept, you might want to consider having a tech come in. I would suggest they replace the ribbon cables first to eliminate those and if the problem still exists, then replace the head. If it's a dealer, they may insist on replacing the head at the same time. Stand your ground and insist upon the ribbons first. You mentioned a support ticket with Roland. Are you under warranty still? If so, get the dealer in there and let them replace both. If it's an independent tech, you may have to have a second service call, as the head is in the $1900 range and most independents will not want to order without knowing they are going to install it.