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Pete, Electronic Engineer
Category: Consumer Electronics
Satisfied Customers: 18102
Experience:  Over 16 years of experience installing and repairing electronics.
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I use an Optoma TS 721 projector. I loaned it to a friend.

Customer Question

Hello, I use an Optoma TS 721 projector. I loaned it to a friend. When it was returned, there are thin vertical black lines that are superimposed on the image displayed. The image is clear and bright. The thin vertical lines are spaced from each other. They appear from the left of the image almost to the right side. There is a small portion on the right that does not display the vertical lines. Any idea as to how to correct this problem? Thanks for your help JC Tellier
Submitted: 1 year ago.
Category: Consumer Electronics
Expert:  Pete replied 1 year ago.

Hi there,

This may be caused by a problem with the input signal.

Have you tried using different input types and input cables?

Are all inputs affected in the same way?

Try using a different input cable, or different input type (e.g. VGA, DVI, S-Video) and let me know if you get a good image..


Customer: replied 1 year ago.

Hello, I tried with two different computers, two different DVI cables. Same results. I will try using the VGA connector tomorrow because my computers do not have such a connector. How do I get in touch with you tomorrow afternoon? Thanks JC

Expert:  Pete replied 1 year ago.


You can just reply back on this question page at any time :)

Customer: replied 1 year ago.

Hello Pete, I tried the projector using the VGA cable. The results are the same. I see the thin vertical black lines. So using DVI or VGA gives the same results. The projection is bright and clear so I believe it doesn't have anything to do with the lamp. So I hope you have a solution for us. Thanks JC

Expert:  Pete replied 1 year ago.

What source are you projecting from?

Are the lines always in the same place?

Could you attach a photo of what is being projected?

Customer: replied 1 year ago.

Hello, I use different PowerPoint. When I boot the computer, the different screens show the thin vertical lines just like the powerpoints. When I use the computer screen there are no lines. I tried with a desktop and with three laptops. None of the computer show the lines when I use their regular screens but when I plug the projector it shows the lines in the projection. These thin lines look like a line of pixel that receive no signal. All the lines start at the top as dashes then become continuous. These lines are spaced about an inch from each other and on the far right side there are no lines at all. I cannot give you a photo before the end of the afternoon tomorrow. I hope that my description triggers a new idea towards the solution. Thank you, ***** *****

Expert:  Pete replied 1 year ago.

Ok, then the input side of the projector is definitely going bad, and the main board inside it will need to be replaced.