When the tv is turned on the green light starts flashing, the fan turns on but the tv does not come on. the lamp will then flash red. sometimes the tv will come on without any problem.

Possible lamp but:

Mitsubishi TV troubleshooting
Here's something that might also be useful. After you turn on the set, and get the regular red blinky lights, hold down the Device and Menu buttons together for about 5 seconds.
The Power light will start to flash in a two digit sequence.
For example, 3 flashes, then 7 flashes = 37.
Here are the error codes, and the corresponding problem:
12 = No error detected, check power supply.
32 = Lamp Cover is open.
33 = Air filter cover is open.
34 = Lamp abnormality
36 = Light Engine (DMD or Lamp Fan stopped)
37 = Exhaust or Lamp Ballast Fan stopped
38 = Lamp Temperature High
39 = DMD Temperature High
41 = Short is detected
44 = DVI cable between FMT and Engine disconnected

Lamp is possible----

Mitsubishi TV troubleshooting
Here's something that might also be useful. After you turn on the set, and get the regular red blinky lights, hold down the Device and Menu buttons together for about 5 seconds.
The Power light will start to flash in a two digit sequence.
For example, 3 flashes, then 7 flashes = 37.
Here are the error codes, and the corresponding problem:
12 = No error detected, check power supply.
32 = Lamp Cover is open.
33 = Air filter cover is open.
34 = Lamp abnormality
36 = Light Engine (DMD or Lamp Fan stopped)
37 = Exhaust or Lamp Ballast Fan stopped
38 = Lamp Temperature High
39 = DMD Temperature High
41 = Short is detected
44 = DVI cable between FMT and Engine disconnected

Mitsubishi TVtroubleshooting
Here's something that might also be useful. After you turn on the set, and getthe regular red blinky lights, hold down the Device and Menu buttons togetherfor about 5 seconds.
The Power light will start to flash in a two digit sequence.
For example, 3 flashes, then 7 flashes = 37.
Here are the error codes, and the corresponding problem:
12 = No error detected, check power supply.
32 = Lamp Cover is open.
33 = Air filtercover is open.
34 = Lamp abnormality
36 = Light Engine (DMD or Lamp Fan stopped)
37 = Exhaust or Lamp Ballast Fan stopped
38 = Lamp Temperature High
39 = DMD Temperature High
41 = Short is detected
44 = DVI cablebetween FMT and Engine disconnected

Inspect the lamp first to see if shattered--set has a self check feature also:

Mitsubishi TVtroubleshooting
Here's something that might also be useful. After you turn on the set, and getthe regular red blinky lights, hold down the Device and Menu buttons togetherfor about 5 seconds.
The Power light will start to flash in a two digit sequence.
For example, 3 flashes, then 7 flashes = 37.
Here are the error codes, and the corresponding problem:
12 = No error detected, check power supply.
32 = Lamp Cover is open.
33 = Air filtercover is open.
34 = Lamp abnormality
36 = Light Engine (DMD or Lamp Fan stopped)
37 = Exhaust or Lamp Ballast Fan stopped
38 = Lamp Temperature High
39 = DMD Temperature High
41 = Short is detected
44 = DVI cablebetween FMT and Engine disconnected

Tv probally needed a new tv projection lamp.This tv has not been change it projection lamp like 1 1/2 or 2 years already?Tv been on and used it like 4 or 5 hours everyday?Yes,than the tv flashing or solid on green LED light is on have a word "LAMP" written on it tv bazel frame?Yes,tv 100% require a new tv projection lamp replacement.

It could be the temp sensor going bad. This sensor sits on top of the metal housing which the bulb assembly slides into. The bulb assembly will have a hole on top and this is where the sensor is above. There is a small blue and white wire that plugs into it. If you pull the wire out and put a paper clip or wire in the coupling you will basically bypass the sensor connecting the blue and white wire. If your tv turns on then that is your problem. Its cheap too. Here were my symptoms..1] Turn tv on 2] Bulb would light up..(which eliminates the ballast) regular picture would show up (which eliminates the bulb and color wheel) 3] 30 seconds later tv would shut down with 3 flashing lights. After bypass the tv turned on as always and hasnt shut down yet. Always un plug tv first. Get the replacement part to avoid overheating and possible fire

The flashing light red power light should only stay while the fan cool down for about 1 minute after a power off (remember to always wait before unplugging the TV so the lamp can cool down with the fan). Does that flashing start right away after plugging back the TV after an hour of letting it without AC power.

The red light should flash no longer than 10 sec. This prepare the light to be turned on. If all is OK the green should stay (no longer flashing) and the sound and picture come on.

As for the lamp flashing, i bet it's only 1 time each 5 sec? Or do it group many rapid flash each 5 sec?

Things that can be wrong:
-the fan lamp

-the lamp is not proprely inserted (wait an hour before manipulating it to be sure it cooled down, and use glove to not put body oil on it).

-Lamps is defective and is not operating properly so you can't get to the usual on screen message that recommend to change the lamp.

Hi,
Its symptoms of weak lamp that need to be replaced.
How old is this TV and did you replaced its lamp recently?
lamp replacement is easy and would be written in user manual. Please buy Sony original lamp for TV safety.
Thanks.

you need to replace the lamp in your tv, it is easy and you can do it. Look on the sides of the set for a door labled lamp, with the set unplugged open it up and remove the lamp, if the bulb is out it will have lots of glass in the lens

Green flashing is normal. Red flashes are error codes. Count the error flashes.

3x - Lamp cover position or cover detect switch bad.
4x - One or more fans failed RPM test
5x - Lamp power supply/ballast failure
6x - Thermal fuse failed (usually)