C 5280 Printer begin power up self-test

[ctwalk]

Two days ago printing color pages this printer worked perfectly .  Today when I turned it on the unit did not go through its normal power up sequence.   Instead it instantly began flashing an orange "!" symbol and displayed a message stating "Printer Cartridge" and below it read "See printer documentation".   Not much information to determine what action to take.   I removed and reseated the print cartridges and power cycled the printer several times but to no avail.  All controls on the front panel have no effect and will not take the printer out of this error condition so I can not run any tests or calibration.  The fact that the last time used (two days ago) this unit printed color copies just fine would indicate to me that the print cartridges are not the problem.  As is I'm dead in the water as this printer is usless to me in this condition.  How could this HP printer turn itself into a boat anchor overnight?

[ctwalk]

I wish to add page 23,  the only page relating to printer cartridges, of my "Printer Documentation"  does not address this problem.   Page 23 contains the same information I found on this support web site.