Print Quality issues with the Develop Ineo+281, need help

I recently bought an Ineo+281 from the local agent here in Kenya. After using it for less than two month, the print quality has really gone bad. I am getting lines on all the solid colours that I print. The local technician has not been able to find out what the problem is. All consumables like the drum, developing unit, belt etc are all above 90%. Attached are images to show you the lines that are appearing on all my prints. Please help identify the problem