So I recently replaced the lamp in my Akai PT46DL10 46" DLP set. What happens is I turn on the TV, after about 25 sec. of the power light flashing green the lamp turns on and I get a picture, the power light is then a steady green. The set operates fine for about another 25 sec, and then the lamp turns off, but I still get audio. The audio continues for another 25 sec or so and then it turns off, and the red lamp light and the green power light are both lit up solid. Also sometimes I will turn it on and the power light will just flash and then the audio will come on but still no lamp. I know the bulb is fine because occasionally it turns on. I am leaning towards the ballast being bad. Any one else have any ideas? I am going to check that the ballast is getting the ~300v supply and ~5v control tomorrow. Note the TV is out of warranty, and I'd like to try to fix it myself before I call a service center.
Update: When I unplug the 5v control wires to the ballast and then plug it back in, the lamp immediately turns on, but then turns back off after 25 sec. or so. If unplug and then replug again I get the same thing. This kind of sounds like the ballast is bad. Anyone have any insight?
I finally got an exact replacement bulb for this set. Same problem as before. I may try the $75 for a new ballast, but I have a feeling that ballast is fine, and that the main processing board is telling the ballast to shut off. Either a sensor is telling it it needs to turn off or there is a problem at the board level.