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  #1  
Old 09-05-2013, 02:40 PM
Bill R Bill R is offline
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ikegami monitor no color issue

I have an ikegami tm20-80 monitor that is loosing color. Color is fine when first powered up, but drops out after only a few minutes. Sometimes I get the no burst indicator, and sometimes there is simply no color. I reflowed a lot of questionable solder connections on the NTSC board around the 3.58mc crystal. Reinsstalled the board and color was back for hours last night. This morning same problem, ok for few minutes then no color. If I leave it off long enough the color will return, but only for a short period of time. I would like to have a schematic or service manual. If anyone can help it would be appreciated.
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Old 09-05-2013, 11:00 PM
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old_tv_nut old_tv_nut is offline
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Is this a tube or transistor monitor (guessing transistor)?
Could be a bad crystal (or the oscillator tuning has drifted) and it kills color when it fails to lock?
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Old 09-06-2013, 04:40 PM
Bill R Bill R is offline
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It is a broadcast monitor from 2003. They do digitally with eleventeen dozen parts what could have been done with a handful of parts in an analogue world. The problem seams thermal in nature, but the NTSC decoder resides in a cage and is not accessible without an extender card that I don't have. I did get the schematics today.
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