Originally Posted by garciab
The replacement lamps are Osram, just like the original. With this tv, it's and easy swap of the bulb into the housing. When the tv fails to power up, there's is a button sequence to press that will reveal a diag code. In this case, I believe the code is 34. But that's just 'lamp abnormality', which can be anything that leads to the lamp not lighting.
I tried the lamp that shut off on him while he was watching tv. And it works fine in my tv (I have a spare I picked up on CL years ago and rebuilt the chassis). So I have no idea what can fail during tv watching and cause the tv to shut off. I'm suspecting the ballast or something in the power supply. He will try a ballast from shopjimmy....after that he's giving up on it.
I hope it's not the color wheel, and that's potentially the item most under stress during operation. I don't know what code the tv gives when the color wheel is shot and it fails to power on. I'll ask him to look for pieces of it when he removes the covers for the ballast replacement.
I've only heard of color wheel problems with Samsungs.
From page 16 of the service manual http://www.scribd.com/doc/40256222/Mitsubishi-WD-62725
III. Lamp Troubleshooting Procedure
If a Lamp Abnormality is indicated and a replacement Lamp Cartridge does not correct the problem, the problem can be due to either the Lamp Ballast or the Electrical Chassis.
•Connect a DVM across pins 1 and 3 of connector CN2 on the Lamp Ballast (See Page 9).
•When the set is first powered On, check for 340 VDC.
•If voltage is good, suspect the Lamp Ballast
•If the voltage is bad, suspect the POWER PWB in the Electrical Chassis
Note that they mention the lamp cartridge
being replaced before moving on to the ballast, not just the lamp. Don't get ahead of yourself when troubleshooting.