9-288 Phaser 7700 Color Laser Printer Service ManualAnalyzing the Test PrintTest prints provide several uses in troubleshooting printer problems.■ Isolating problems to either the print engine or to the ImageProcessing Board and host software.■ Locating feed and paper transport problems.■ Detecting print-quality and image registration problems.Using Test Prints to Isolate a Problem to the Print Engine or to the ImageProcessing BoardYou can use test prints to determine if a problem is caused by a faulty printengine or by a faulty Image Processing Board or host software.Note This procedure presumes you have investigated anydisplayed error code or message. If not, please do sonow.1. Print a sample image from the host computer.2. Enter Printer Diagnostics and generate a test print.3. Compare both prints.4. If the problem occurs when you print from the host computer but does notoccur when you print from Diagnostics, the problem may be in the ImageProcessing Board, in the print driver software, or in the application softwareon the host computer.5. If the problem occurs when you print a test print, then the problem is in theprint engine.Note You can also use the above procedure to assist indetermining if a print-quality problem is caused by afaulty print engine, Image Processing board or hostsoftware. If the print-quality problem is an imageregistration problem, refer to “Adjustments andCalibration” on page 4-123 of this manual for instructionson adjusting image registration.Using Test Prints to Locate a Feed or Paper Transport ProblemYou can use test prints to locate a problem with paper feed or with papertransportation along the paper path.Note This procedure presumes you have investigated anydisplayed error code or message pertaining to paperfeed or transport problems. If not, please do so now.1. Enter Printer Diagnostics and generate a test print.2. Follow the paper along the paper path to locate the cause of the problem.
