I have a mitsubishi ws-65909. We had a power
I am a proud owner of the same TV you have. A couple of months ago, we had repeated, intentional rolling power outages in the Dallas area in an ice storm. I had the blinking green light of death also. The problem is in your DM module. If you remove the back panel on the set and expose the boards, the DM is the one farthest to the left. It is actually located inside a metal frame that surrounds it. You can disconnect the wiring harnesses coming out of it to the other boards. You may have to label the harnesses, but typically they are labeled so you can simply match the numbers of the harness removed to the receptacle into which it was originally plugged. There should be about 5 of these to remove. I recommend using needle-nose pliers, as they can be very hard to unplug. Just don't squeeze too hard and crack the plastic.
Once you have disconnected and removed the DM board assembly, you will need to remove the metal housing and disconnect another series of wiring terminals in order to fully expose the power boards within. Make sure you keep track of which screws go where, as some may be longer than others. Phone pics of wiring harnesses can come in handy so you remember where they go. After the metal housing is removed, you will see an elevated, smaller board attached to the much larger main board. The small PC board needs to be separated and removed so you can hold it in your hands and work on it. At this point, you have the option to take the board to an electronics repair shop or to fix the problem yourself (as I did) and save yourself some money. A decent repair shop should remove and replace the defective components for about $20, PARTS INCLUDED!. There are 7 capacitors that need to be replaced. They cost less than 50 cents apiece at an electronics parts supply shop. You may find them at RadioShack, but I recommend an electronics supply shop. This way you can buy capacitors that have a higher voltage rating than those originally installed. A higher voltage rating is recommended and will in no way affect performance or outcome. In fact, the original caps (capacitors) were rated too low in terms of both voltage and temperature. I believe the original caps were 1000 uf (microfarad), 16-volt caps which are black in color - indicating they are 85 degree compliant. Look for 1000 uf (microfarad) capacitors with a brown color that indicates they are better for high-temp applications of up to 105 degrees. You will be able to clearly see on the cap that it is 1000 uf, 25 v, 105 degrees C. One very important thing to note is that a defective cap isn't always obvious and will NOT always display symptoms of a bad cap. Typically a bad cap will have an outward bulge on the top, like a soda can about to explode. It may also show signs of dark, caramel or black colored syrup-like liquid oozing out of it. This should be considered, but definitely not ignored. When I fixed my set, ALL of the seven replaced caps actually looked like they were brand new and showed NO typical signs of fatigue or failure. I replaced all seven anyhow, put it all back together, and brought it back to life and saved myself many hundreds of dollars. The primary point I wish to relay is that you do not rely on the apparent physical appearance of the caps to decide their state. I hope this helps any and all with the symptoms related to the constant blinking green light which responds to nothing on the Mitsubishi WS -65909. You CAN save your TV by spending less than $75 by doing it yourself (less than $15 if you have a soldering iron and solder) or take it to a ****** who won't do component-level repairs and will just replace the whole DM board for 700 bucks or so. I know these sets are old and rapidly being replaced by LED, Plasma, and LCD sets, but you can't beat the pic for the price. If I get enough requests, I will figure out how to post a video how to to do the whole thing. I hope this helps. This will fix the constant blinking green light with no power-up on the Mitsubishi WS-65909 rear-projection TV!