NEC MT850 Projector Problem

Believe it or not we still use these old ass projectors at my work. Why? Cause they still work well in most situations and we have lamps that need to get used up.  Noticed a strange problem with several units in which the green channel (G in RGB) was shifted to the left (or right depending on the software orientation) by about 6 pixels. This problem is manifesting itself across several units after about 7+ years of use. I pinpointed it down to IC3404 “3 Channel Video Amp” by Mitsubishi M52307SP which seems to be faulting. BIG GASSFACE to NEC for letting me know that a digital service manual exists but is not available because they no longer have parts available for projectors manufactured before 2007. Here’s to keeping these out of a landfill for a little while longer.

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2 Responses to NEC MT850 Projector Problem

  1. Holly says:

    hit here! my MT850 has a green shadow to the right of the image and a red one to the leftt. do you think replacing the video amplifier will fix this problem?

    thanks!

    • admin says:

      Try spraying IC3404 with a component cooler like GC Electronics’ Freeze Mist II. If the shift fades away that chip is defective and a replacement might work. I wasn’t able to find a cheep supply of that IC so I never did swap one. Good luck!

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