Benq MP772 ST Projector with Redish image

[CidiRome]

Hi.

I have on hand one Benq Projector with a RED image.

This situation only happens with image from RGB sources and the RGB pass through output (to monitor) is good.

When I see a color pallet, the red appear as white, Green and blue appear black.

If I connect something to the Composite Video port the image appears correct.

I suspect the MST9883C-LF chip that I believe is the AD9883 I've seen being referred in a service manual of a similar projector as the digitizer of analog RGB graphics into three 8-bit channels of red, green and blue data.

I've re-soldered it in case o some bad solder being the problem, but got the same result.

Do any of you think that this chip could have failed or can this be a problem with other source?

Best Regards.

[CidiRome]

Re: Benq MP772 ST Projector with Redish image

Hi.

I've replaced the MST chip and que problem remains, so the problem is elsewhere.

Does anyone have the service manual this specific projector?

Best Regards.

[CidiRome]

Re: Benq MP772 ST Projector with Redish image

Hi.

I discovered what was the problem.

It is the EL4340 that has two bad buffers.

At the beginning I did't thought of this "switcher", but when I noticed that the projector don't switch the RGB output (for a monitor) it became evident. The RGB output only outputs the RGB1 input.

I'm waiting now for a replacement.

Cheers.

[CidiRome]

Re: Benq MP772 ST Projector with Redish image

Hi.

Just to update this.

This chip (I mentioned on the previous post) was replaced and the projector is working like a charm.

In fact another projector arrived after this one with two malfunctions and one was this same chip with all the three bad buffers (if I can remember correctly).

Hope this helps someone.

Cheers.