If you have a Dell 1800MP projector with flashing orange LEDs and not
able to turn on the power, you can try using my method below.
WARNING: Try it at your own RISK!

1. Unplug the power cord from the projector, then put it in your freezer
for about 30 to 60 minutes.
2. Take the projector out from the freezer then plug the power cord back,
you should still have the same problem with the orange LEDs flashing.
3. Take out your hair dryer, set it to medium heat and blow the warm air
into the projector (air vent next to the power plug – see picture above).
4. In about 1 to 5 minutes, your projector should have the blue flashing
light on the power button.
5. When you get it to work, don’t ever unplug the power again. I had to
do this every time the power went out, and it worked every time.
If you don’t want to try the above medthod or couldn’t get it to work,
you can try repair it yourself, but it’s not going to be easy though.

Tools and replacement part
Original Part
Mtr: Ost
Part: Electrolytic Capacitor, Low ESR, 3300uF, 10V, 105C
Note: I couldn’t find the right part at Fry’s Electronics, therefore I bought the
NTE VHT1000M16 (1000uF, 16V, 105C). The capacitance is a little less than
1/3 the original part, but I wanted to give it a try anyways. And guess what?
It works!

Remove the power supply to replace the bad capacitor (3300uF 10V).

The rest of the parts. These must be removed first before you can get to the power
supply.

Remove the solder shown in the picture above and pull out the bad capacitor.

Check your capacitor polarity when replacing capacitor (just like battery).
I will add video later, showing how I repaired mine.
Good luck!
See what others are saying:
http://en.community.dell.com/forums/t/19295558.aspx
http://www.fixya.com/support/t1902295-lamp_power_flashing_amber