Well, with a code 61 --
You would THINK the TV's engine was actually BAD !!
I have seen the spark as the ballast tries to light. Seems to me that if it was the light engine ...
You WOULDN'T GET THAT SPARK !
And I agree with you. You would NOT get that spark.
So...now we actually have to double-check that the ballast is actually sparking, because it will determine whether your Lamps are the cause or the Engine is actually bad.
So, let's get the rear cover off of your TV set, then remove the lamp, and make sure the Door switch is either jumpered or activated so the TV will turn on, then you can listen or LOOK at the new ballast and make sure you get CONSISTENT sparking on your Ballast. We get consistent sparking, your engine is working, and delivering the Lamp Enable signal that turns on the ballast.
And when it shuts down...you can see if you still get the Code 61 when the lamp is disconnected. You may get 66....you may get 34....or you may get 61 and all would be due to the lamp not being plugged in.
Either way, I believe your lamp just isn't up to the "required standards" of a Mitsubishi Original lamp.
Been there....done that. You get what you pay for.
Run that test. Ballast fires consistently, you get that sparking and your engine is OK.