CurtPalme.com Home Theater Forum

wfogg · Joined: 02 Jun 2008 Posts: 7 Location: Madrid - Spain

Hello everybody, let's see if anybody has an answer for this.

My red and green lenses (or tubes? I don't know) have very strong burns (?). Does anybody know what they are and if it has a solution? They both are exactly in the same part of the screen and the blue one doesn't have any sign of it. I was thinking about sending the projector to the recycling point but I thought I could ask first just in case there is a not very complicated and expensive solution.

If there is not an easy solution and anybody wants the projector I would gladly give it away instead of seeing it die. In this case I can tell you that if the problem is in the lenses and not in the tubes, the blue tube as a slight projection mark and the red and green tubes seem to be in a good condition, and the projector works perfectly. The only thing is that the projector is in Madrid, I don't know how many of you are close to Madrid. Rolling Eyes

These are pictures from the disaster:

So... what do you think?

Thank you in advance!!! Very Happy

**kal** · Posted: Wed Sep 09, 2020 6:30 pm Post subject:

Hard to be 100% sure these are most likely burn C-elements which are the closest lens element to the tube phosphor surface. This happens if sunlight is allowed to enter the front of the lenses (lens caps should be on or lenses covered whenever moving a CRT projector outdoors just to be sure).

I know there's been some disaster stories like this in the past with similar pictures but for the life of me I can't find them.

Kal

**kal** · Posted: Wed Sep 09, 2020 6:33 pm Post subject:

Found one of the threads:
https://www.curtpalme.com/forum_archived/viewtopic.php@t=21402.html

Changing a C-element (assuming you can find replacements) is not an obvious job for most people. See here for the procedure on the newer Sony G90: http://www.curtpalme.com/Sony_G90_C_Element_Change1.shtm

The c-element is the attached to the tube surface and the area between the two is filled with glycol (liquid). So it's permanently attached to the tubes. The lens assemblies then sit in front.
Here's a pic from a completely different projector where the tubes have been removed and you can see the curved c-elements attached to the 3 tubes. The green and red c-elements are often tinted like this for better colour reproduction:

Kal

wfogg · Joined: 02 Jun 2008 Posts: 7 Location: Madrid - Spain

Thank you very much, Kal. Really.

I have seen some videos about changing C-elements and the glycol, when I thought it could be fungus. It is not definitely something I can see on my reach, so there in no solution for this.

So I think I must say goodbye to King Kong. As I said if somebody is interested in it for parts or because you think you can repair it it is yours. Obviously feel free to pick it up in Madrid or if somebody wants it shipped I can help with that. I'm moving out of my apartment on the 15th, but maybe I can keep the projector there until October, or maybe even later.

If anybody is interested let me know. Wink

I will also posted it in the Buy & Sell: https://www.curtpalme.com/forum_archived/viewtopic.php@t=42516.html

Thanks everybody. This forum is great!

**kal** · Posted: Wed Sep 09, 2020 7:40 pm Post subject:

Definitely not fungus. I'm pretty sure it's a burn on the c-elements, especially given that it's in a line (happens as the sun moves). You can remove the lenses (easy - it's just 4 bolts usually) to confirm.

Kal

**kal** · Posted: Wed Sep 09, 2020 11:21 pm Post subject:

I guess the bigger question is: It sounds like this is a projector that you've had for some time? Did these marks just suddenly appear? Or did you leave it outside while you were moving or something? If this is actually burn from sunlight that doesn't just happen with a projector sitting in a home theater.

Kal

**AnalogRocks** · Posted: Wed Sep 09, 2020 11:36 pm Post subject:

Did you leave these out in the sun? Or move them outside few a few minutes with no lens caps on?

wfogg · Joined: 02 Jun 2008 Posts: 7 Location: Madrid - Spain

**kal** · Posted: Thu Sep 10, 2020 11:57 am Post subject:

If it happened over time I don't think it's a c-element burn from the sun then as that happens almost instantly. Like taking a magnifying glass to wood or paper and focussing sunlight.

Kal

wfogg · Joined: 02 Jun 2008 Posts: 7 Location: Madrid - Spain

They did take time to appear, or to grow. In fact the first time I noticed something was in winter 2019 and it was a slight lost of definition in that area. I saw it growing but I didn't know what to do to stop it and I don't know why I never thought about posting it here, my fault. I really don't know how much sun they receive in winter (if that is the problem).

I imagine that whatever the problem is the solution will require to deal with the C-elements and the glycol anyway. It definitely doesn't seem like a problem with an easy solution. If you feel curiosity about it, or because you think there is something to learn here, if there are some other photographs I can take for you to see it better let me know and I'll do my best. If I have the time, a member of the forum contacted me to see if he can get it and I have to finish moving.

Thank you again!

**AnalogRocks** · Posted: Sat Sep 12, 2020 10:59 pm Post subject:

You need some glycol, C elements and a place to take it apart. Ohh and a set of lens caps.

wfogg · Joined: 02 Jun 2008 Posts: 7 Location: Madrid - Spain

Thank you all for your help and suggestions. My projector became an organ donor and a big part of its boards went to Austria where they helped another Sony 1292 recovering from is problems and working again.

I'll continue taking a look around here, a G90 has always been my dream, and... who knows. Smile

dvh99 · Joined: 25 Dec 2009 Posts: 2158 Location: nederland

**kal** · Posted: Tue Oct 27, 2020 5:41 pm Post subject:

Yeah, yeah. He understood what I meant. Wink

The sun does move however. The entire universe is expanding. Wink

Kal