HP Color LaserJet 1500 Service Manual - Page 220

Functional checks Note Engine test The engine test is used to verify that the print engine is functioning correctly. The formatter is bypassed during an engine test, so the engine test is useful for isolating printer problems. Because the engine test prints horizontal lines along the entire printable area of a page, it is also useful for checking and adjusting registration. Printing an engine test The engine test switch is inside tray 1, on the left side, just below the front cover. To print an engine test: 1 Turn off the printer. 2 Turn on the printer. 3 Open tray 1 and load paper. 4 Press the engine-test switch (shown below). The HP color LaserJet 2500 series printer formatter must be connected to the ECU to perform an engine test. Otherwise, the printer does not print the engine test. Figure 120. Note Location of the engine-test switch Performing a continuous self-test 1 Turn the printer off. 2 Press and hold the GO button. 3 Turn the printer on and continue to hold the GO button for 10 to 15 seconds, or until the Attention and Ready lights turn off. 4 Release the GO button. The device lights begin cycling from front to back. The self-test process runs until the printer is in the Ready state. This test is similar to the NVRAM initializer; for more information see "NVRAM initializer" on page 221. 218 Troubleshooting Q2488-90901