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Optoma HD20 DLP Projector – Dark Spot Repair

It Could Be Caused by a Burnt Lens That is Easily Fixable

Can You Find the Dark Spot Problem In This Image?

Can You Find the Dark Spot Problem In This Image?

Optoma HD20 DLP Projector

Optoma HD20 DLP Projector

The Optoma HD20 is a fairly popular DLP projector with a 1920 x 1080 native resolution and an attractive price tag. It also seems to be afflicted with an unusual tendency to suddenly develop a diffused dark area (sometimes inaccurately described as a blurry area) that may obscure part or nearly all of the projected image.  This sudden darkening may also be accompanied by a strong smell of melting plastic, because as in the case described here, plastic is actually melting and charring.

I had been looking for a full HD projector to use to build a high-resolution 3D printer, and I ran across this unit suffering from the dark spot problem on Craigslist for $100.  I was aware that projectors with this problem could be user-repairable, and when I looked at the unit I was able to see enough to determine that the large dark area on the right side was indeed caused by a melted inner lens.

Almost Unbelievable Meltdown of Internal Plastic Lens

Almost Unbelievable Meltdown of Internal Lens

The cause of the dark region on the projected image is an oddly-shaped aspherical plastic lens that is the final element in an optical path that channels light from the reflector lamp on the left front of the unit. … Read the rest

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