HDTV Forum

ksbarnz, thank you for posting to this thread!

Guys, I have not received one phone call over this problem that seems so common on your end. Geez, these are 2006 TVs and if it is so common then why has it not come up? It has not even come up with my colleagues! What this means for dabhome is it may be tough to get an ASC to respond to this properly.

My million dollar question is this... if you grabbed 10 people off the street and they looked at your TV how many would quickly see this for themselves? Is it obvious to any neophyte? Videophiles can make a servicers job way more difficult no matter how right they are. TV service is not the ISF and it does not come with an ISF calibrator except for a hand full of shops around the country!

At first it was barely noticeable and it progressively got worse. At first it would have been hard to see if unless you knew what to look for but as time went on it was really noticeable. Bright objects would bleed over onto dark backgrounds. Do a quick search for Mitsubishi blooming problem on the rear projection forum at AVS and you will see that it has been a problem for a few people. Some with multiple light engine replacements, like myself.

Finally saw one today, WD65732, it is the light engine.

Extended warranty and manufacturers warranty
Provide your symptom and arrange for a service call and there is no need to tell them you think it is the light engine. Hopefully the result will be the tech stating it is the light engine.

Out of warranty
You must call a Mitsubishi Authorized Service Center and arrange for a service call and there is no need to tell them you think it is the light engine. Hopefully the result will be the tech stating it is the light engine. At this point you either pay for the repair or contact Mitsubishi for assistance.

Good Luck!

I'm a little late to this problem (just found this forum with a google search for "dust in light engine") but my 65831 had the halation issue, and it WAS the light engine.
Fortunately, I bought a service contract thru Magnolia/Best Buy and I experienced remarkably good service. Tech came out and saw the issue (white bleeding into dark backgrounds). He ordered an exchange light engine which was drop shipped to our home. He then came out and installed it and our 2+ year old TV had a new life!
It was startling how much the original light engine had deteriorated the image contrast!
I was itching to do a post mortem on the old engine, but the tech took it back with him.
I'm an EE and have worked for GE with imaging systems for many years, and I'm certain there was dust/grime accumulation somewhere in the internal light path. This engine has no less than three fans, and the screen on the projection lamp appears to be capable of filtering out small birds and that's it.
This seems like a fundamental issue, and replacing light engines is not very cost effective for ensuring clean optics!
My 2

While you may have a point with other MD technology DLP does not require cooling of the optical light path, cooling is all external.

I have no idea if the problem is a broken seal and debris getting inside or the breakdown of an optical element at the molecular level.

Richard wrote:While you may have a point with other MD technology DLP does not require cooling of the optical light path, cooling is all external.

I have no idea if the problem is a broken seal and debris getting inside or the breakdown of an optical element at the molecular level.

Thanks for the quick reply!
I'll hope this was a one of a kind failure. I can understand a molecular breakdown. There's got to be tons of UV coming from that lamp! At any rate, the image is stunning and the service contract is good for almost another 2 years, so all is well.
Bruce

Don't mean to beat a dead horse, but here is a query and response from Mitsubishi, FYI.

-----Original Message-----
From: Bruce Anderson [mailto:[email protected]]
Sent: Friday, February 13, 2009 2:56 PM
To: MDEA Service
Subject: WD65831 TV

Dear sirs:

I currently own a WD65831 TV, S/N 101006, purchased 11/25/2006, and I
am very happy with it except for one issue.

The lamp was replaced under contract on 11/06/2008 and I recently
noted a loss of contrast and a loss of detail in black areas, with
light scattering around bright objects on a dark background. This was
most noticeable on the bottom of the screen and it exactly mimicked
the consequence of dirty optics.

Our excellent service technician replaced the entire light engine and
image quality returned to stunning - just like new! I recalibrated
with my DVE disk and image quality is now simply superb.

Fortunately (for me) the TV is under contract. The bad news is that
the contract expires 11/25/2010. My concern is that this is an
expensive way to maintain reasonable image quality.

How do I prevent this from happening again? We are non-smokers, have
a central vacuum system and live in Oregon, so environmental dust
should not be an issue. The projection lens is easily accessible, but
can the light engine internals readily be cleaned? Any suggestions?

Looking forward to your response.

Bruce E. Anderson



From: [email protected]
Subject: RE: WD65831 TV
Date: February 23, 2009 12:59:38 PM PST
To: [email protected]

Thank you for contacting Mitsubishi Digital Electronics America, Inc.
We are pleased to be able to assist our customers via our website. Here
is the information that you have requested:

Everything that you are doing is excellent. The previous light engine
was just defective. You shouldn't have any further problems as it seems
that you take excellent care of the TV.

MDEA Service

I've been in and out of this forum on the problem of apparent loss of contrast with what appears to be a dirty lens in my Mitsubishi 65831 TV's light engine. I had the engine replaced under contract which totally cleared the problem. I am noticing a return of this issue and started a search to find out what is going on. I came across this:
http://www.avsforum.com/avs-vb/showthread.php?t=1148792
which corroborates my original theory that a lens surface INSIDE the light engine is the culprit, and that this issue may be more widespread than originally thought. It looks like a once a year cleaning or sell the damn thing.