HP CP6015dn Service Manual - Page 537

Heartbeat LED The heartbeat LED indicates that the formatter is functioning correctly. While the product is initializing after you turn it on, the LED blinks rapidly, and then turns off. When the product has finished the initialization sequence, the heartbeat LED pulses on and off. The heartbeat LED will perform the following sequences: 1. The LED blinks with four fast bursts at power on. 2. The LED blinks at a fast, steady rate during memory testing (one blink per 8 MB). 3. The LED stays off for about eight seconds, while the boot code is decompressing, before the display turns on. 4. The LED blinks at a steady rate of two blinks per second for the remainder of the product operation. 5. If these sequences are not performed, check the following: ◦ Reseat the memory. ◦ Replace the memory. ◦ Replace the formatter. 6. If the control panel display does not illuminate, perform an engine test to check the engine. You must have paper loaded in Tray 2 for the engine test. Engine-test button To verify that the product engine is functioning, print an engine test page. Use a small pointed object to depress the test-page switch located on the rear of the product. The test page should have a series of horizontal lines. The test page can use only Tray 2 as the paper source, so make sure that paper is loaded in Tray 2. Figure 7-13 Engine-test button 1 ENWW Engine diagnostics 495