Just Replaced lamp, but lamp light still on, and projector not working

Have reset the lamp hours after installing the new lamp? If, not the projector has treated the new lamp as old lamp & refusing to light further. So, reset the lamp hours to zero. To reset the lamp timer do as follows. Plug the power cord into the AC socket of the projector. Switch ON the power of the socket. (not projector) While pressing simultaneously INPUT, ENTER & UNDO on the projector, press ON on the projector. "LAMP 100%" is displayed, indicating that the lamp timer is reset.
If this does not correct your problem then the problem lies in other area. Let me know so that further I can provide you solution. Above things are preliminary

Looks like there is power supply problem as well as the lamp.

1 Clean all filters
2 Check out power supply (usually a few capasitors need to be replaced)
3 Wuld be a good idea to check the lamp in wokring projector, but if the "Lamp" light is constantly on it is more likely a faulty lamp as well.

The lamp is not lighting.
Check all lamp and reinsert. If you have just bought the lamp contact the supplier.

This is the excerpt from the manual on how to reset the lamp life timer.

Turn on the projector and use "Lamp Reset" after the lamp module is replaced.
Lamp Reset: (i) Press "Menu" ?§ (ii) Select "Options" ?§ (iii) Select "Lamp settings" ?§ (iv) Select "Lamp Reset ?§ (v) Select "Yes".

Same thing happened to me (By jschmidbauer on Jan 14, 2010). How did you fix it????

Smetimes the other fan comes on when set to full bright. As your lamp is not lighting up, the other fan will not come on. If yo have replaced the lamp and it is still not working, then 9 times out of 10 it is will be the ballast.

if you remove the lamp, inside the lamp housing you will see a refraction (fly-eye) lens. these evenly distribute the lamp light. the one on the other side from the one you see (there are always 2 lenses) is probably burnt and needs replacing (a common problem with lcd projectors). you will have to send it in to nec. in many of their projectors, both lenses are in one assembly.

there are several other issue that can arise with this unit

you may want to check out fixmyprojector.com

Replacing the lamp with an old one was helpful for me. Good news: the projector itself not faulty. Bad news: I have two projectors with the same issue at the same time (the lamps were replaced also at the same time) after only 400 hours of running.