Tool/software:
After replacing the DLP7000, the DMD does not work. Please let me know the possible causes.
When looking at the reflected light from the DMD in its initial state, thick horizontal lines appear to shine strongly.
Do I need any initial settings?
Dear Fizix-san
I tried taking out the DMD and cleaning the contacts with alcohol and cotton swabs, then reinstalling it, but that didn't solve the problem.
However, the brightness and darkness appear to be slightly different.
I have one question.
When the interposer and the guide plate on the board are tightened to the specified torque, the board will be slightly deformed.
This can be understood by the fact that the force is applied to the three protrusions that support the DMD due to its structure, so unless the board sandwiched between them is kept floating, the DMD cannot be held down, but the board bends. I don't think we can make good contact with this, but how should we approach this?
Masahide Hayashi
Dear Fizix-san
Thank you for your answer.
Today I'm going to try loosening the screw and then gradually tightening it 1/4 turn at a time.
The specified torque is shown in the attachment. Please provide documentation of the revised recommendations.
Other information:
1.At first, there were light and dark stripes, but after DMD operated only once, it became uniform.After that, the problem cannot be reproduced because DMD does not work.
2. When I increased the output of the LD and observed the reflected light from the DMD, the reflected light appeared to be uniform.Attached photo (last)
Could you please provide an explanation of the possible mechanisms for these phenomena and any clues to solving them?
Dear Fizix-san
I have a report and a question about the situation after that.
After releasing the torque, I gradually tightened it to check the condition, but there was no change.
I noticed that there was a difference in the gap between the DMD board and the boss of the interface shown below, so I first checked the dimensions to see if it was okay to manage it with torque.
The variation is within 0.1 mm, including measurement error, so the fact that the gap is not the same means that the reaction force of the leaf spring is not equal on the left and right, so the actual pressure on the board is not uniform.
So, I checked the light in a state where the gap was equalized instead of the torque, and the reflected light in the initial state was uniform. (Attached photo)
However, the DMD is still in a state where it does not work.
So, my question is, the backer plate in the figure below is probably made of aluminum, but if you know the reason for this material selection, please let me know.
If you want to apply pressure evenly without deforming the board, I think it is better to use a plate with high rigidity and flatness.
At present, we suspect that because this plate is deforming, it is causing the board to deform as well, which means that uneven force is not being applied to the 150 contacts, causing the malfunction, so if there is any reason for this, we would appreciate it if you could let us know.
This time, we don't have the time to leave it for 8 hours, so we will need to work on it again at a later date to check, and at that time we would like to try changing the material of the backer plate if it is okay.
Dear Fizix-san
I think both the front plate shown in yellow in the diagram and the backer plate shown in red in the diagram are aluminum alloy.
The board is TI DLPLCRC410EVM.
I have attached a photo of the gap and the DMD peripheral parts.
The control board was made by ViALUX, and the specified torque was provided by ViALUX. It is expected that the structure of the DMD board will be different.
Dear Fizix-san
The gaps are illustrated with arrows.
We have also asked ViALUX questions and requested their cooperation.
Although we have not seen the DMD board made by ViALUX, we were asked about the difference in structure since information on the tightening torque was provided.
Dear Fizix-san
We thought that the problem might be caused by the DMD board, so we purchased a DLP7000UV board unit from your company.
I tried replacing it, but the result was the same, horizontal stripes were visible in the initial state, and the DMD did not work.
I am using a control board made by ViALUX, but I think there may be a problem on this side.
Could you please give me some advice on how to check if there is a problem with the control board and what to do about it?
Dear Fizix-san
As for the situation after that, the horizontal stripes of the DMD reflected light disappeared during the first operation the next day and it worked.Therefore, I think there is no problem with the control board.
However, even though I didn't do anything to it, it was in an unstable state, sometimes not working.
I think the reason it worked properly was because the flex cable connection became more stable. What do you think?
Assuming that the cause is an unstable flex cable connection, it would be necessary to control the tightening method and torque.If you have any such know-how, please let me know.
Also, is there any harm in reattaching the flex cable over and over again?
Thank you for your advice.
I have attached photos of the state in which the DMD's reflected light stripes have disappeared, and the state in which the stripe pattern has changed due to cable replacement.
I don't know the details about the build, but can you tell anything from the picture of the control board?
