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RCA 50" DLP M50WH74SYX1 Burn marks?    
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Pmunky



Joined: 11 Nov 2009
Posts: 2
Location: USA

PostPosted: Wed Nov 11, 2009 2:34 am    Post subject: RCA 50" DLP M50WH74SYX1 Burn marks? Reply with quote

Hi I searched on the forums for issues like this but could not find any so I am posting what I think maybe unique.

Ok a little background story. I have a RCA 50" DLP TV Model:M50WH74SYX1 about a year of ownership I started having an issue with the TV loosing picture but keeping sound and the power cycling itself, after about an hour of use(after searching I find that to be a common issue). I'm no TV tech but I work on computers for a living so I thought it sounded like a thermal issue. If I place a fan behind the set it will stay on all day with no issues. Take the fan away and set will lose picture and so on. So the set was still under manufacturing warranty. Called them, told them the issues. After the first 3 service calls the set was still not working correctly. I believe only the bulb, the main board, and one other part(not the color wheel I am sure of that) has been replaced with still no resolve. So I just said screw it and used the TV with the fan for another year. I final decided to get the set repaired. I bought an extended warranty for the set at time of purchase through GE. NOW the story gets good. They send this guy to take a look at the set. He is telling me it could be the color wheel or a thermal sensor\fan issue. While is at my house to just take a look cause he has no parts with him. He decides to clean the set with compressed air. I had my back turned and started to walk away when a heard BOOM(not a whoosh). He was using the compressed air duster while the set was on! My first thought was the bulb blew and now there is mercury in the air. I made sure the TV guy was ok and told him to get out from behind the TV and come out side with me(not sure why I had to tell him that tho he should have known already). So I tell him I wanted a replaced TV that I did not trust any of the components in the set now. After he left I aired the house out and pulled the bulb myself to make sure it was not busted, it was still intact. Long story short I was able to get a check for the replacement value of the set. So I know that was a long story and hope you enjoyed hearing it.

The set still has the original issue, plus now what looks like burn marks on the screen I have attached two images.The burn marks are best seen on solid colors. The set still has all the colors and the burn marks are static and do not move. So here is the question, is this something that just needs to be clean or maybe its the color wheel(not sure how they work so I'm just guessing)? I have even thought it could be the polarized film(Not sure if a DLP TV would have that) on the inside of the screen that has gotten flash burn?

If anyone could suggest a fix I would grateful, also a place to purchase the parts I would need. I had a hard finding parts for this model out the bulb that is. I just think if it only cost a couple of hundred dollars it would be well worth it. Sorry I am so long winded So if you're still reading this thanks Smile



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Jesse Mack



Joined: 22 May 2008
Posts: 600
Location: The Last Frontier

PostPosted: Wed Nov 11, 2009 11:19 am    Post subject: Reply with quote

Don't know about the "boom" vs "whoosh" issue but the pictures suggest a contaminated light engine or burned filters within the light engine.

Wanting your cake and eat it too eh!! If you have been paid for the set it would seem the the logical thing would to be to THROW THE SET AWAY!!!!!

Light engines are assembled in a clean room and are not usually servicable and no internal parts are available.

Jesse
Pmunky



Joined: 11 Nov 2009
Posts: 2
Location: USA

PostPosted: Wed Nov 11, 2009 2:14 pm    Post subject: Reply with quote

Jesse Mack wrote:
Don't know about the "boom" vs "whoosh" issue but the pictures suggest a contaminated light engine or burned filters within the light engine.

Wanting your cake and eat it too eh!! If you have been paid for the set it would seem the the logical thing would to be to THROW THE SET AWAY!!!!!

Light engines are assembled in a clean room and are not usually servicable and no internal parts are available.

Jesse


The "boom" vs "whoosh" issue concerned me since a "boom" would suggest compression. Where as a "whoosh" would suggest a free floating gas igniting in air. I was tring to give a accurate description when asking for help that is all.

As in wanting my cake and eating it to. Yeah maybe, but it wouldnt hurt to try and fix that is fixable. Isn't that why this forum is here?

If you feel the light engine is the issue then I have the TV recycled.

Thank you for your reply.
Jesse Mack



Joined: 22 May 2008
Posts: 600
Location: The Last Frontier

PostPosted: Wed Nov 11, 2009 4:09 pm    Post subject: Reply with quote

Great response. Not many people will call a spade a spade.

As to the light engine. You need to answer a question as to the possible damage done to your set.

Was this condition apparent right after the air was injected and/or did the discoloration exist prior to the air injection.

When you inject compressed air into a tightly confined area it sometimes sounds like beating a drum.

If your answer is that you had a clean picture (no discoloration) prior to the air being injected the discoloration is most likely dirt/dust contamination inside the light engine. It is usually a very bad idea opening up a light engine as like I said before they are assembled in a clean room, have a dust filter, and then room air is run thru them for cooling purposes in the home. I know, it's a stupid process, but it is still the truth.
When injecting air, all of the dirt on the filters and inside of the engine would be stirred up and could cause this symptom.

If you are brave, the only suggestion I could make would be to remove the light engine, take just the light engine apart and remove all dust/dirt. Then take the unit to the cleanest room you have after settling all of the dust down with water mist and recleaning and reassembling the engine. Keeping in mind that if you drop any of the filters or reassemble the engine incorrectly your results will be as bad or worse as before you started.

However, if the discoloration existed prior to the injected air, the filters are burned and are not available which makes the set a toaster.

Hope this helps.

Jesse

PS:
If you decide to disassemble, the color filters CAN be installed backwards. The filters on a light engine are made of glass and pass only a partial spectrum of light and reflect the rest.
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