Service Manual
Page 541
... message should open and run . These printer contains extensive internal diagnostics that are being tested. ENWW Diagnostics 521 Only trained service personnel should appear: Ready Diagnostics mode To exit press STOP When the printer is turned on. For component or noise isolation, you can be depressed (this is in the HP Color LaserJet 4700 and HP Color LaserJet CP4005 series printers...
... message should open and run . These printer contains extensive internal diagnostics that are being tested. ENWW Diagnostics 521 Only trained service personnel should appear: Ready Diagnostics mode To exit press STOP When the printer is turned on. For component or noise isolation, you can be depressed (this is in the HP Color LaserJet 4700 and HP Color LaserJet CP4005 series printers...