Hi,

a friend of mine got a commercial projector (epson, don't know the type yet) from his employer.
The reason he got it was because they dropped it and the colours are wrong since they dropped it.

it is projecting a blue image with a white border. changing the keystone settings only changes the blue image, not the white border.
While playing a dvd, you can see the image moving and the subtitles, so it is definetly projecting the input. What I noticed, was that the subtitles were black with a white shadow, so the colours are inverted.

We opened it and couldn't really find something wrong.
I noticed that one of the orange flat wires (fcc?) connected to the lcd's was not seated very well. pulling it out and putting it back enhanced the image a little, but didn't have an effect on the colors.

does anyone know what might cause the colours to be inverted. could it be one of the mirrors that reflect a colourq and let the other colours pass that is placed backwards (I don't know if the employer tried to repair it himself). could it be the fresnel that is backwards? one of the lcds not being connected well. or a lens backwards?

I don't know where I should start looking, so any hints or links to theory are usefull and might help.

thanks in advance

Johan

HI, do you think the lcd panels inside might be broken, if not then what i would guess has happened is when the projector was dropped 1, 2 or all 3 lcd panels inside might have got displaced because these are held by very thin metal frames which are all held by screws. thats why sometimes you might see rptv with ofsetted colors or 3d like image being projected. I did that once while looking whats inside a projector and when i placed it back i saw allignment guides for each panel which i did not care much and i got the same problem that you are having now. there is something called pixel allignment for projectors, projector techs know well what i am talking about, try to search on it .

Thats only a suggestion.

Can you take pictures of the projection and/or the insides?

If you do take pics of the projection, can you feed it a computer signal and display some test images, i.e. red/green/blue, and a grayscale?

No, that's not it. the lcd's are glued to a beamsplitter of something like that (the cubic that combines the three light collors back to 1 signal to be send to the lens.

I had another look at it. I checked the different LCD's by unplugging them 1 by one and check the result. All lcd's had a similar impact so that lead me to the conclusion that it's not the LCD's.

I looked at the different lenses, mirrors and filters and that also seemed impossible to have such an effect. (a badly placed mirror cannot invers the colours). I had a better look at the controller board of the LCD's and the I found what causes it.

Apparently there is 1 chip which is placed right above the ldc's and beamsplitter that has been more or less ripped off from the board. There are still 3 or 4 of the 10 pins connected, some can be resoldered, but for 3 of them the patches on which the pins were soldered were also ripped off. I asked another friend who tests and repairs printboards of thomson cameras to have a look at it.
as the patches were ripped off, I would have to solder the pins directly on the points where the transmission lines go to the other side of the board with a little wire. The thing is, for one of the ripped off patches the line moves under the chip and there it goes to the other side of the board.
This will be tricky to solder and I don't have the tools for it so if I find someone that can help me with it I could try resoldering it.

anyway, I guess this loose chip is the reason that the collors are not good. It must be some kind of NON port inversing the colours. I'll first try to find the chip on the internet to find out more about it.

thanks for helping. I'll let you know if I succeeded in resoldering (or letting anyone else resolder it).

Johan

sorry, forgot to take pictures off it. as I know know what is wrong I don't see the point of taking pictures anymore. I already feeded it a computer signal to display specific colors. Changing colors had effect but the colors were wrong. It was not one specific color that was prominently visible.

Johan

HI Johan, are you in the UK or USA. If you are in the UK i have seen adverts where people repair circuit boards, they can also remove and fix all kinds of chips as well. I think some laptop techs do that as well.
You have people who can help you with it, good luck. Hope you see light on the wall very soon.

You can try using a chip socket with wires or extra long leeds.

Then you don't have to worry about getting to circuit board under the chip.