The light tunnel that channels the light after the color wheel on this set
fell apart. It consists of a small metal channel with four mirrors glued to
the inner sides. The glue got brittle and one of the mirrors fell into the
light path. The result was a shadow on one side of the pix. The set is
less than 2 years old.

Optoma's solution to the problem is to replace the light engine. They do
not, however, have any idea if the replacements use the same glue.
Obviously, their choice of adhesive was inappropriate. This stuff was
completely brittle and the rest of the mirrors simply fell out when I
removed the one in the light path. They have no suggestions for a better
fix than just replacing the light engine.

My question is this, is anyone familiar with high temperature adhesives that
might be appropriate? I found an epoxy at an auto parts store rated to 300
degrees F and that should be good, but I don't know how it will hold up with
extended exposure to lower temps and the UV from the lamp. I went ahead and
tried it and the set is working fine for now, but I expect to see more of
these before long. We sold a dozen or so of these sets when they were one
of the best looking DLPs around, and they are mostly between one and two
years old.

Another option might be to use a light tunnel from another set. Some use a
solid light tunnel rather than a channel with mirrors. This would, of
course, solve the problem if it had the right fit. Anyone have much
experience with many DLP engines and the design of various brands? We just
have not had many break yet, so my experience is limited.

Leonard

Leonard Caillouet wrote:
The light tunnel that channels the light after the color wheel on this set
fell apart. It consists of a small metal channel with four mirrors glued to
the inner sides. The glue got brittle and one of the mirrors fell into the
light path. The result was a shadow on one side of the pix. The set is
less than 2 years old.

Optoma's solution to the problem is to replace the light engine. They do
not, however, have any idea if the replacements use the same glue.
Obviously, their choice of adhesive was inappropriate. This stuff was
completely brittle and the rest of the mirrors simply fell out when I
removed the one in the light path. They have no suggestions for a better
fix than just replacing the light engine.

My question is this, is anyone familiar with high temperature adhesives that
might be appropriate? I found an epoxy at an auto parts store rated to 300
degrees F and that should be good, but I don't know how it will hold up with
extended exposure to lower temps and the UV from the lamp. I went ahead and
tried it and the set is working fine for now, but I expect to see more of
these before long. We sold a dozen or so of these sets when they were one
of the best looking DLPs around, and they are mostly between one and two
years old.

Another option might be to use a light tunnel from another set. Some use a
solid light tunnel rather than a channel with mirrors. This would, of
course, solve the problem if it had the right fit. Anyone have much
experience with many DLP engines and the design of various brands? We just
have not had many break yet, so my experience is limited.

Leonard



Are these light engines being replaced under warranty? Are they taking
the old ones back? Spare light engines that you have repaired with
better glue can be a very valuable asset.