Hello there and welcome to Just Answer. My name is XXXXX XXXXX I will be assisting you today. I am an engineer with over 30 years of electrical and electronic training, repair and installation experience. I will try and answer your question accurately and precisely so that we can get you on your way.
Now..is this the green light on the front?
If so, unplug for 5 full minutes. Plug it back in. Does the blinking start then or after you press 'On'?
Please let me know so that we can continue.
It starts as soon as you plug it in.
Ok, before I give you what I think it is, let it flash for one or two minutes.
If it does not become solid afer 2 minutes, let me know so that we can continue.
It's the front light. It does not stop blinking.
You have a failing DM Module. The module handles various sub systems in the TV and has a small power supply board with either 4 or 7 capacitors on it. The caps fail and the DM Module fails to handshake with the other systems in the TV and the green LED blinks. The blinking is normal until handshaking is complete, then it becomes solid.
The TV cannot boot without the DM Module.
This failure is very common on all Mitsubishi projection TVs from the past 10 years.
If you want to fix it, this is what is involved on a similar set (nice pictures): http://www.jeremyburns.com/Mitsubishi-Green-Blinking-Light-Fix.pdf
To have it professionally removed, repaired and replaced is going to cost you upwards of $350 if you can find someone to take it on.
Let me know what you think. I'm sorry that there is no quick and easy fix.
Thank you Steve.