HP 1200 Service Manual - Page 151

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. The engine test prints horizontal lines down the entire printable area of a page and is also useful for checking and adjusting registration. Printing an engine test The engine test switch is inside the left cover, below the formatter. To print an engine test, remove the left side cover. See "Left side cover" on page 80 and depress the engine test switch. A single test page will print. The formatter must be connected to the ECU to perform an engine test. (See callout 1 in figure 65 on page 121.) Otherwise, the printer does not print. When you remove the left side cover, you must override the door interlock (SW 301). (See "Paper path check" on page 155.) 12 Figure 73. EN Engine test switch Functional checks 149