Originally Posted by slgrieb
You have a bad formatter. The formatter controlls PowerSave Mode and data processing for the printer. If the fuser were bad, you would see the system come out of PowerSave and then generate a 50.X fuser error message. Printer error messages override PowerSave. The error message will alternate with PowerSave.
Of course, depending on the number of pages run through the printer, you might need to replace the fuser, but if that were the case you should see an explicit "perform printer maintenance" message. I suggest you print a menu map.
On the control panel press MENU until INFORMATION MENU appears, then press ITEM until PRINT MENU MAP appears and press SELECT. This will show pages printed, normal maintenance interval and so on. If you are close to the 200,000 page normal maintenance, go ahead and suggest that the customer do the regular maintenance while you are replacing the formatter. The maintenance kit for the specific printer has all the needed rollers and a fuser assembly. Your customer's nose will bleed when they see the price, but if it is all due soon, it is less expensive to do it in one call.
You should also be aware that print quality issues like the gray background may be independent of printer hardware problems. These can be caused by crappy aftermarket cartridges (mostly out-of-spec photo drums), paper that fails to meet HP specs, or excessively dry paper or paper that is loaded upside down.