CurtPalme.com Home Theater Forum

[jarseneau]

I was looking over a G90 today for potential purchase and found on all 3 c-elements, patches of tiny dots like pepper about an inch below center and wondered if this is something that can be cleaned off? I didn't see anything in the projected image but it was just roughly setup on a wall. I can tell it is definitely on the C-element and not the CRT because I could move my head and see the patch stay in place on only the c-element. The attached picture is just a photoshop representation of what it looks like..

Anybody know what this is?

[CIR Engineering]

Well, the tube looks great. I would guess that it is just some dirt that settled on the c element. If you pull the c elements you may be able to clean them. But I wouldn't let the spots stop me from buying the projector if you can't see them on the screen.

You should try and find a proper green color corrected c element for the g90 anyway. So you would replace at least one c element. You could also change the blue c element easily as clear ones are not difficult to get at all.

If Curt doesn't have them, I also have G90 green c elements here as well as clear. I have a box full of Sony greens that will never get used I also have clears, but I am sure Curt has them.

craigr

[draganm]

[CIR Engineering]

[cmjohnson]

If those are pepper spot burns, then you may want to pass unless you can live with those spots always being present on the projected image. Bring up a full white screen first, and look for discolored spots. Then bring up pure red, green, and blue fields, and look for black spots on the image. Know that if they're there, they'll never go away.

Can you live with that, given the price?


Retubing is possible but it's not cheap!


CJ

[CIR Engineering]

If they are spot burns I would not buy the G90. Spot burning tubes is not normal for a G90 and there is probably something wrong with the projector if it is spot burning tubes. You can change the tubes, but if it happened once it could happen again and then you would just have new spots on new tubes.

You could ask to remove a c element to inspect the spots. Do you know how to do this without dumping coolant all over the place?

craigr

[Clarence]

[jarseneau]

Thanks for your input guys. I can say for certainty that the spots are on the C-element because I can look at a point on the CRT's surface, move my head and see the pepper move relative to the burn in. (there is burn in that I can use as a reference and the tube you see in the above picture is only an illustration using somebody else's tube picture) From the history of the projector, I was probably the first to remove the lens in the 10 years since it was installed in a light controlled room with no sunlight, no smoking). If I had to guess it's just some dust that was trapped there and baked at the point where the weight of the lens brought the C-element and the aft of the lens closest together. I brushed it lightly but didn't want to get more aggressive since I was just inspecting it. I bet it would just disolve with the appropriate cleaner. The lenses looked dust/smoke free and pristine. I didn't notice the pepper on the lens but it would be a lot harder to see and I didn't think to look real hard.

What would G90 c-elements go for and what would be a recommended cleaner?

[LOTREE]

For cleaning probably ethyl alcohol, vodka or eye-glass cleaner. I find the latter works great. Rubbing alcohol leaves smears.