If this is a straight line than yes you need to change the light engine or at least the DMD board. This is not something that happens to often on HP TV's so I think it will be hard to get a guide online.
DLP's are manufacture very similar, with 2 modules each module mounted in a sliding chassis.
Most probably left side module will be for all the PCB's (TV Boards), and right module will be the light engine.
a Light engine will look something like this:http://photos.discount-merchant.com/pho ... id=1187327
You can see the DMD board in this pic, is located inside the rectangular metal cage with circled openings. The last 2 pics on that link will show you the DMD board expose. It will be wise to open that cage and get the part # for your DMD so you can look for it online.