I'm newly registered. Have read many of the posts in this excellent thread and have an issue that I thought the great minds like Mr. Bob could help with. I'm not ruling out a paid phone consult either. I purchased this Mitsubishi WS-65869 brand new on 9-11-2002. Have enjoyed and continue to enjoy the picture vs. current panel technology.. Over the last several months, the picture has developed the symptoms shown in the attached screen shots. I have twice returned the set to operation by replacing the 7 caps on the DM module PS board. I just replaced the coolant in the blue gun hoping it was part of the issue since the coolant has never been changed. To my surprise, the 10 year old coolant was nice and clear, and there was no crusty build up on the lens. White text on black screen results in dark band across the screen, which I have seen when editors try to put nice crisp white titles on black background. To prevent the overshoot, most editors put a 1 or 2 pixel blur to soften the light to dark transition..
On another forum, there was a similar problem described which ended up being a bad cap on the CRT PCB. That makes sense to me, but I'd like opinions of those who work with tv circuits on a regular basis. I have a degree in electronics and had amateur radio and FCC first class licenses many moons ago. I went the route of semiconductor fab equipment tech after college that ended up being my decades long career before leaving to start a video production company. Most of my alignment skills are geared towards the camera end of things using wall charts.
I share Mr. Bob's opinion about CRT PQ. I worked for Sony in their booth at NAB and when they brought out their OLED production monitors, they placed two of them next to a CRT in a darkened demo area. It took a few minutes,before I was able to pick out the CRT. That shows just how nice the black levels and contrast can be with OLED. I'm trying to keep the Mits in operation until OLED for the living room comes out of the stratosphere in terms of pricing.
Thanks for any advice you can give me. I know my way around the circuitry but unfortunately, I never invested in a good scope for the house. I was spoiled because I was able to check out nice tools from my employer for personal use on a short term basis. I do have a good Fluke voltmeter though.
Here are he screen shots...