Problem started with strange new relatively loud rhythmic thumping sound whilst printing. All the start up and routine sounds ok. Successfully printed out Supply status and self test/configuration page at one point after switching printer off and on but with a multi-page document, page 1 was perfect, page 2 lighter, page 3 yellow and page 4 and onwards progressively feinter yellow only. Now it won't apply any toner at all and paper emerges as white as it went in.
The cyan low light is on (est 544 pages remianing) but no other warnings or relevant status logs.
Any idea how I definitively confirm what is at fault? I have a service manual and am happy to tackle the issue but with no printer engineering background would not know what was faulty or not!