I bought my 9900 off eBay with no guarantees about the printer working. There was no ink installed and so I purchased new carts and Piezoflush to send it through the lines. All the electronics and motors seemed to be functioning correctly so I did an Initial Fill and let it sit for 48 hours then did the Initial Fill again. Ran a nozzle check and nothing printed. Checked the carts and it seems that no Piezoflush has made it out of the carts into the lines after two Initial Fills. They are all still full although it shows the waste tank to be filling (although no Piezoflush is making it to the waste tank). So can the lines be so blocked that the Initial Fill cannot even occur? This seems to be where I am at unless I can poke it with a stick some more. Any thoughts?
I suggest cleaning the waste ink vacuum pad + letting the head sit on some piezoflush overnight and then doing another few maintenance cleanings to see if you can break it up. Instructions for this are in our documentation section on this site (inkjetmall.com/tech).
If this does’t work you may have to resort to manually flushing the head with a flush kit (mostly built for small format but with care this can work on a LF printhead as well).