Compaq MP1600 dlp projector repair?

[Satamax]

Hi everybody!

My name is Max and i'm french. I have done sopme research, and understand how DLP projector works. I searched up and low about how to repair thoses. Basicaly, i've bought a cheap one on ebay, it works but has a color drift, the blues get black and the yellow and reds don't show much, the yellow is near transparent, and reds turn yellow to orange.
*I was thinking it could be three things, the cable, but that's verry optimistic.
*Or the filter which has gone either south in color or it's synchronizing which is bad.
*Or the input circuitry of the red or yellow which puts out too much or not enough light!

Can anyone help me to repair that one? I'd like to find a schematic for that compaq MP 1600 too. As for troubleshooting tools, i have two DMM and two osciloscopes, one ten mhz analogic and a five mhz digital. I know a bit about valve amps (well enough to work on sound cities) if that can give you an idea about my electronics skills.

Thanks a lot and best regards.

Max.

[Satamax]

Hi everybody!

Litle update, cable is good.

Best regards.

Max.

[ace3000_1]

heya max take the colour wheel out and hold it upto the light, see if red is red, blue is blue ect, to me it sounds like your colour wheel is out of sync or its faded, eitherway if this is the case id replace the colour wheel and maybe if no good after that try to resync the colour wheel speed, a good way to test the sync is to make a total blue, red and green screen with a paint program in windows and see what colours u get projected, if u have a new colour wheel filter in place and the colours are out its definatley the sync that causing the probs.

Trev

[Satamax]

Hi Trev!

Thanks a lot for your reply! I'll test the wheel later on! With the screens first, what is the base color? Green blue and red, but what exact color, i have photoshop, therefor i can manage a good color. As well, i've opened it earlier on, and the wheel seems to have faded. Doesn't look verry red to me, viewed from an angle.

Best regards.

Max.

[Satamax]

Hi everybody!

Hi trev.

Well, it's not the wheel, as the colors are ok! It's either the synchronization, or the input circuitry. Anybody has an idea on what to do next? How to check the circuit, and the synchronization of the wheel. the test with blue red and green screens didn't work at all. None of theses were restituted the proper way. Thought i can have reds and blues, on some pictures fidling with photoshop.

Best regards.

Max.

[golftdibrad]

If you think about it, the color wheel doesn't start and stop in the same place every time. And over time the motor may spin it up to speed slower that it did when new. So there has to be a sensor near the DMD device to tell the DMD what color it is right now or was a click ago. Mabye this sensor is bad. Perhaps the wheel is on backwards? If it is a rgbrgb wheel and was on the wrong way, when the sensor saw blue, the dmd would think red is next when the actual color would be green. That would cause funny color shift. How many hours on this thing? The motor itself may have cashed in because it no longer maintains speed. After rereading you post I think the latter is likely. Does it ever flicker? does the shift slowly get worse and then get better all the sudden?

Hope i gave you some ideas,
Brad

[Satamax]

Hi everybody!

Brad, thanks a lot for the reply! Yes you gave me ideas. I was looking at the sensor earlier on, and vas wondering about that thing, it has two litle leds. The wheel is a blue red green and white one. and can't be put backwards i think. I've received a reply from HP/Compaq.

Here it is "Hello Mr. D,

Thank you for contacting HP Total Care.

Unfortunately, I would not be able to send you a schematic of the
digital projector as it HP confidential material. However, I do
have some suggestions that you may try.

Firstly, try adjusting the color saturation as well as the color
temperature in the on screen display. If this fails to correct the
issue, try a factory reset. Try connecting the projector to a
different source using a different cable. If the issue is not
corrected, then the issue is most likely being caused by the projector
and not by the video source or the cable.

If the projected image including the on screen display, are tinted
with a certain color, and the above steps have failed to resolve the
issue, the projector will need to be sent in for service. To set up
this service please contact technical support at the following number:
0892 69 60 22 Mon-Fri 8:30-18:00.

This should resolve the issue. If you need further assistance, please
reply to this message.


Sincerely,

Tim

Factory reset gonna be the next step. And in the meantime, if anybody has a schemo and is willing to share it, i'd apreciate. Or if ever someone knows which pot to turn to slow or speed up the wheel. Or adjust the colors. I'm afraid i'm such a newbie to this, that i need someone to walk me through.

Best regards.

Max.

[msx-2]

i think your doing great , would be even better if you could show some pics of the inside of the projector. I am quite curious about how these things look (i.e. i don't have a clue how the dlp chip looks like ,or how small all parts are (probably very very small compared to our 15" tft-projectors))

[Satamax]

Hi everybody!

It's repaired. The wheel was touching the wheel cover, a litle piece of card and a resync, and i was done. MSX, i'll try to take a pic soon.

Best regards.

Max.

[ace3000_1]

great! great news max, sorry for not replying to your posts earlier i wasnt aware u had posted, some how i never got the emial and missed u along the lines, anyway its working now and u can enjoy the projector once more lol.

all the best
Trev