HP LaserJet M9040/M9050 Service Manual - Page 361

Glass scaling calibration NOTE: Before beginning the calibration, perform the tray registration calibration on the print engine. Touch Administration, then touch Print Quality, then touch Set Registration, then touch Source, and then select a source. Touch Test Page, and then touch Print. Follow the instructions on the printed registration page to complete the registration setting. Perform this procedure for all trays. 1. Download the MFP calibration target and the MFP calibration values chart. Calibration targets are available at the HP service information Web site. 2. On the product to be calibrated, print the calibration target on ledger or A3 paper. 3. Print two copies of the calibration values chart on ledger or A3 paper. 4. Load the calibration target face down on the glass with the left edge of the calibration target toward the back of the glass. 5. Copy the calibration target. 6. Align the top line of the copied calibration target to the top line of the original calibration target. TIP: Be sure to align the lines and not the edges. 7. On the calibration target, compare the line at the bottom of the original to the line at the bottom of the copy. 8. Determine whether the copied page should be lengthened (line shifted down) or shortened (line shifted up) and by what distance in millimeters. 9. Using the two calibration values charts, determine the value for the glass scaling to enter into the Service menu. Plain motor speed calibration NOTE: Perform this procedure after replacing either of the ADF motors to ensure that the media feeds through the ADF at a uniform speed. After performing this procedure, immediately perform the ADF front and backside scaling procedure. ADF motor speed calibration reduces speed variations to produce high-quality copy and scan images. This section describes the procedure for calibrating the ADF motor speed for plain media. This procedure requires the use of the A3 or Ledger motor speed calibration target. The correct target must be printed on the correct corresponding media size; otherwise, ADF motor speed timing issues can occur. TIP: Download the calibration motor speed target page from your technical support ASP Web site. Calibration targets are available at the HP service information Web site. 1. Perform the set tray calibration procedure for Tray 3 (you can use letter- or A4-size media for this step). 2. Load Tray 3 with A3 or 11x17 media. 3. Print the calibration motor speed target page from Tray 3. 4. Place the target original face down in the ADF tray with the arrow pointing towards the paper feed direction. 5. Make a 100% scaled simplex copy (make sure that you print from Tray 3). ENWW Other diagnostics 343