RCA 50" Scenium Screen has dark top?

[scuba1954]

I have a HDLP50W151 RCA tv. I have owned this since Feb.2004. I purchased the extended warranty and had two bulbs and one ballast replaced. Now the tv is out of warranty. The first bulb and a ballast was replaced 06/2006 and the last bulb was replaced 11/2008. I had the last bulb replaced at that time because the warranty was set to expire in a couple of months from then. I told them the picture would go black then come back on (same problem I was having in 2006). Thought I should get a bulb replaced before warrany expired because at that time the bulbs were over $700.00. About 3 months ago I noticed that the top of my screen has gotten darker all the way accross and it goes down about 3 inches. This is not a solid line it is like a smoke color. You can see through it with no problem. If the program is darker you would not notice this darkness. If the screen is bright like the sky or snow then this darker is very noticeable. If I replace the bulb will this correct this problem? It has been two years since the bulb was replaced. I have never seen this darkened edge on my screen in the past. Any help would be appreciated. Thanks in advance.

[grayfox]

I would suggest trying the lamp first, but if inside that gray area at the tp you can make out the image without coloration, it can be an indicator that the colorwheel has reached the end of its lifespan. This is one of the consumable parts inside a DLP that needs replacement at least once during your TVs life span. This is almost always indicated by a humming, maybe even screeching sound.

[scuba1954]

I have replaced the bulb and still no change. Far as the color wheel making noises, there are no noises at all. I think I read somewhere on this site that I may be experiencing a tunnel collapse??? Not sure what needs to be done to fix this or if this is something that I can do myself? I changed the bulb and cleaned out everything with no problems.

[grayfox]

Yes if the tunnel shifted, moved or "collapsed" then it is a physical change in the tunnel where the light shines through, you would have to slide out the complete optical block and make shure the are no cracked parts, and more importantly that it is set all the way in because if the tv was moved around recently this can simply be the lens shifting from its focus point on the screen.

[scuba1954]

The TV had not been moved when the dark area appeared. It seems to me that in the post about the light tunnel on the RCA Scenium TV that someone posted the part name that RCA calls the tunnel. I looked it up then and found it but since then I have forgotten what it was called???

[grayfox]

hhmm... do you have any images of the distortion?

[brbrem]

Just joined the forum and wow I'm glad I did. I too am having the light tunnel issue as described on my RCA HDLP50W151. Can you give me some pointers on the removal of the light engine? I’m very mechanically inclined and have no problem opening up the back of the tv. I have worked on dlp projectors before so I am not afraid to jump in. I’ve seen some postings on the net that people have repaired the light tunnels due to collapse. My issue is very slight but exhibits all signs of the mirrors have collapsed or are in the process of shifting. The tv still has a great picture! I hate to have to replace it. Can the light tunnel be replaced? I cannot find a part number online. Thanks for your help! :D

TIA
Brian

[grayfox]

hello brbrm!

Have you taken a look at the guides on the homepage?

[brbrem]

[grayfox]

wow yeah I imagine its possible, but I have personally have not calibrated the mirrors myself, unless one fell completely out of its holding... is this the case?

[brbrem]

grayfox the mirrors have not fallen at all. They have shifted much like a parallelogram due to heat is my understanding. My understanding is that the mirrors are glued together as a rectangular box and the heat from the bulb causes the glue to soften and allow the mirrors to shift. Am I right to assume that this is indeed what happened? This seems to be a simple fix if it can be done. I hate the thought of spending $300.00 for a light engine if this is all that is wrong. What are your thoughts and you mentioned calibrating the mirrors? Haven’t heard this? Thanks for your reply!! I need all the help I can get. ;)

[Colorado]

try in the user settings of the tv switching the lamp power from brighter to longer lasting ...you have no idea how many times this fixed what people thought were bulb or color wheel problems ( and if it works for you it is an earlier indicater the bulb is going bad and sometimes if its a generic bulb they cant run on bighter setting because of heat issue with the bulb)

[grayfox]

hhhmmm Colorado have you done that before? I have not :(

[brbrem]

[brbrem]

Ok. Just checked. It's already on long life. Is removing the light engine pretty straight forward? I'm very mechanically inclined and not afraid to take it on. My background includes high end audio and restoring vintage audio equipment, but it’s not my profession. Thanks again for all your help!

Brian

[Colorado]

yes grayfox I have done this before as a matter of fact my own rca hd61lpw165 does this if I put it on brighter setting it flickers and goes mosaic and if I put it on longer life setting it is fine so it either has something to do with the bulb but I was also thinking it might have to do with the balast also... to get brighter setting I would think the balast has to send a bit more voltage to the bulb ......it makes sense anyway


And the light engine is easy to work on if you remove the screen...... do not try getting to it from the rear

[brbrem]

Remove the screen? Really? My understanding is that the light engine removes from the rear. Is this correct?

[brbrem]

Well I ordered a rebuilt light engine from TSM rather than try to fix the light tunnel. The light tunnel is no longer available for purchase. Are there any tips or things I should be aware of when installing the new light engine? The removal of the existing was very easy. The interior was remarkably clean for being used for the last 7 yrs. I cleaned what dust that accumulated and blew out the electronics. No caps were bulging and the ballast looked damn near new. No signs of heat or malfunction were visible on the ballast. I took pictures as I removed the light engine. Any and all tips are appreciated. Thanks guys!

[brbrem]

A couple more pics.

[brbrem]

Update: Well I was able to get my hands on a light engine and removed the light tunnel from it and install it in my existing light engine. To my amazement I now have a incredible picture! Wow!! The Scenium lives on one more time. Question to those who have the Scenium tv, I have a sticker on the back of the light engine that says Software 1-4. Anybody else have this sticker? I tried to install a replacement light engine but it would not work. Only my light engine would work in my TV. :D