When you open the back cover door to replace the bulb, the lamp timer should automatically reset but if it doesn't then try either one of the next options:
Press the SYSTEM RESET button on the front panel with a pointed object, such as the point of a pencil or end tip of a paper clip. The green LED will flash quickly for about one minute.
When the green LED stops flashing, you may turn on the TV. The changes you made most recently, before using SYSTEM RESET, may be lost. Changes you made previously, however, are not lost.
1. Select any device from the Input Selection menu.
2. Press MENU followed by 1 2 3 to open the Reset Service Menu. CAUTION: All settings except V-Chip will be reset to the original factory defaults Read on-screen warnings before proceeding, as some user data or settings may be erased.
3. Press ENTER to reset TV defaults.
Here is the link to download your TV manual:
http://www.fixyourdlp.com/blog/2009/04/ ... jection-tv’s/