72HM195 ballast issue? Any experience replacing?

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72HM195 ballast issue? Any experience replacing?

Postby MartiniMan » Thu May 19, 2011 1:54 pm

Hello all, new to the forum, thanks in advance for any help!

I have a 72HM195 which is about 5 years old. It still runs very well, love the TV. However, about 6 months to a year ago, a small problem started. In doing research on the net, it seems it might be a ballast issue, but I'd welcome any opinions.

The TV will occasionally "lose" a bit of brightness in a spot (usually to the right of the screen) - it just fades out slightly until the scene changes, sometimes the brightness fade will "drift" (slightly move) if the scene is long enough. Also, particularly right at a scene change, I'll hear the lamp "ting" as if it was just turned on. Usually it's when the scene changes from a darker to a brighter one. These issues are usually not noticed by others, and not terribly distracting, so I haven't been in a hurry to fix it. However, I was thinking this week "just look into it and see if it's a simple fix or not". If it helps, the problem started when I had a power loss to the house (I have an excellent surge protector, so I don't think it was a surge, just the loss of power might have been a catylist to the problem).

So, my questions: Does it seem like the ballast is a good asumption with this problem? On an older model such as this, is the ballast replacement relatively easy? Cost? Where would you buy a ballast online from?

Thanks again!

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Re: 72HM195 ballast issue? Any experience replacing?

Postby BYO » Thu May 26, 2011 11:57 pm

:geek: Hi MartiniMan,

This doesn't sound like a ballast issue, but a DMD board issue.

If it was a ballast issue you would notice a dimmer picture in the whole screen.
But if is just in one area is most likely to be a DMD.

:!: Please read and watch the video on the following links, which will help you understand how image is created:
http://www.dlp.com/technology/how-dlp-w ... fault.aspx

After watching does links, you can comprehend that some of the pixels in that dark area are switch to the OFF position (just some of them not all). For that reason you do have a image but just dark, and when the image changes to something brighter all of the pixels starts working properly again.

:idea: :idea: There is nothing you can do to get it better unless you change the DMD board or the DLP chip.
You can prevent to get it worst by optimizing the ventilation inside. Make sure the TV has room to breath dont have it near a wall, allow it to breath. You can also add a fan on the back pointing towards the air vents which will provide coller temp inside. And you can also vacuum the inside of the TV.
[color=#40FF40]Change is the only constant, we must become the change we want to see. [/color]

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