Need Help HP Latex 260 - Maintenance #3 message - stops everything happening

I wonder if I can ask for some help...
HP latex 260.
I keep getting this "Maintenance #3 contact support" message and it won't print what the RIP sends. It is waiting to be fixed.
I can to a head test print ok. Looks good.
The funnel is now clean. The waste bucket is new . The air filter and tubes are clean.
I can't seem to reset whatever it thinks needs doing in "maintenance #3."
It's holding up the works... and I'd appreciate any ideas, on how to get it to move along and accept the RIPped file, thanks.

I tried getting into 'setup' to reset the counter for Maintenance #3, (which relates mainly to the waste bucket, funnel, tubes etc) but I cannot even get there.
Ian

 

Thanks everyone very much.
This one would not print while it displayed that message, but I replaced the waste ink bucket, air/ink spray filter, tubes and funnel, and cleaned the carriage rails and oiled them - and the message remained.
So I went into set-up mode and reset the SMK3 counter, rebooted it, and all is good now- printing again.

Thanks again