Why is my printer only outputting faint blue prints?

I have an old Epson AcuLaster C1000 that was stored for a number of years. The network status page shows a warning and the slow blinking green status light means some consumable is running low. The problem is I've no idea which.

It prints in faint Blue but all four toner cartridges seem to have plenty in them. As you can see the print page almost gets all the way out but not quite. I wondered if it could be the fixer oil bit but I'm unsure. Is there a way for me to see a more precise error code?

I've got the user and service manual (you can download them if you search online). So I should be able to pull it apart if I knew what to look for.

I created a video of it printing and the output so that you can see and hear it in action: https://www.youtube.com/watch?v=nY3Ohd00...