Well, I got my C-Drive and now all of a sudden the glass in front of the green tube is cracked and make parts of green blurry. There are several large cracks extending from the center? Is this dangerous? I have no idea how it happened. There are some bubble at the top. I just want to know the CRT isn't going to explode/implode or whatever.

Thanks

Thats too bad,

Does the tube still work if so I'd assume it is fine. Did any glycol spill? If so you need to get it out NOW before it corrodes the electronics. Your best bet now is to pull the tube and asses the condition.

It could have also been caused by not bleeding the tubes and glycol pressure building up when it was heated by the tube (this would be my guess)

You may also want to look up tube bleeding on Curts site so this doesn't happen on the other tubes.

Erik :(

I bet the pressure built up since i think mike had the tube in storage for awhile when he switched to digital. Old tube will absorb moisture into the glycol and when you use it again after a long period of non use it can heat up building pressure and either explode out of the front glass or into the tube itself. Sounds like you got lucky and its just the glass on the outside. Im sure it can be replaced. Not sure what type of glas you will need but i read some threads on this over at curts site/forum.

athanasios

Will replacing the tube be enough? Isn't the glass in front of the tube on the tube itself? BTW, a little bit of glycol leaked out, but not too much. The tube does still work.

Yeah you could replace the whole tube but if your ambitious the glass itself can also be changed and you keep the tube and your money ! the tube has a pane of glass that keeps the glycol inbetween the tube glass and the glas that broke. But You could always get a new tube and keep the old tube as a project for a rainy day.

Athanasios

Yeah you could replace the whole tube but if your ambitious the glass itself can also be changed and you keep the tube and your money ! the tube has a pane of glass that keeps the glycol inbetween the tube glass and the glas that broke. But You could always get a new tube and keep the old tube as a project for a rainy day.

Athanasios


How do I keep the liquid from spilling out and how do I replace it? The tube does sort of need replacing anyway.

MTyson,
http://www.curtpalme.com/Bleeding_CRT_Tubes1.shtm

Use a syringe and suck it out then let drain all the way. Two fill screws under the silicone dots.

Save the fluid then you can use a razor blade to remove the broken glass. Find a burnt tube to use as a donor for the glass as well as a bit more glycol. Replace glass with RTV black silicone and cure for a day or so. Use distilled water if needing to rinse out. When refilling leave a small bubble for glycol expansion. Bummer but the tube will be fine if you are careful with it. Done a bunch of them. Doug

Send the tube to VDC. I think it's $100 to change the glass. Most likely pressure cracked the front glass. It's a bitch to change yourself. If you don't, then glycol will continue to seep out, and you'll destroy the tube phosphor.

Curt's right if you haven't done one before. I thought they charged more. It would be the safe way. The mounting lug has to be real clean as well as the glass for a good bond, I use 99% alcohol and let dry good first. Doug

MTyson,
http://www.curtpalme.com/Bleeding_CRT_Tubes1.shtm

Use a syringe and suck it out then let drain all the way. Two fill screws under the silicone dots.

Save the fluid then you can use a razor blade to remove the broken glass. Find a burnt tube to use as a donor for the glass as well as a bit more glycol. Replace glass with RTV black silicone and cure for a day or so. Use distilled water if needing to rinse out. When refilling leave a small bubble for glycol expansion. Bummer but the tube will be fine if you are careful with it. Done a bunch of them. Doug

I'm confused about replacing glass with RTV Black silicone. Where do I find glass of the right shape and size?

I have never removed a tube before. How do I do this and do so without killing and/or painfully electrocuting myself. I'd rather go with any digital than to have that happen.

I did this repair to the blue tube on my 1031q. It wasn't that hard to do. Just takes a bit of time to do it right. Double check the seal before putting the tube back into service.

It's a royal PITA with the NECs, as I think the front safety glass goes in from the back of the metal frame, which means you need to take the raw tube out without smashing it.

Trust me on this one, with the questions you're asking, SEND IT TO VDC. THis isn't a newbie procedure to do...

There are newly posted instructions on how to take the tube out on my site below.

Is this a PG? When I sold mine I stressed to the buyer that they should check for the air bubble and drain some glycol if needed.

This isn't an issue for XG LC's right?

I haven't seen it yet, but the tube construction is the same on the non LC models, so I'd say YES, check for it. I'm now bleeding all of my NECs right when they come in the door.

Don't LC models have rubber bellows that expand and protect the glass? Or, rather, the C-element?

Yes, that's why I said non LC models..:)

Gack. :o Jesse asked about XG LC models and I didn't notice your clarification.

So,... nevermind!!

Are you bleeding the LC models, or don't you bother with that?

I suppose I really ought to bleed my 8500 before I re-mount it...... ick

So, is it easy or hard to remove a tube without electrocuting myself? If not I will stay with digital.

Look on Curts site and decide for yourself.

I don't think it's too hard, I would just make sure I knew what I was doing before I started

One thing I hate about the NEC is it's a pain in the ass to converge without having a point board. It seems no matter what I do or for how long I can't get it to align nearly as well as I'd like. There is always a chunk of on color off on the grid. I have worked for hours and it just seems hopeless to converge.

Wish I wouldn't have spent $72 on a new C-Drive. This is going to be more expensive than I thought.

It takes a while to really understand/master all the interactions that happen when various settings are modified. I reconverged mine, wiped it out and started over many times over the period of a couple weeks before I really got the hang of how everything was going to interact. Doing a rough convergence is pretty quick but even now (after a year and a half of doing it a LOT) I'll put quite a bit of time into it whenever it gets slightly off.

My Xtra has very solid convergence except the outermost edges (which are pushed just off the edge of the screen anyway) and I use no point at all. I just wish it would warm up faster so I didn't have to suffer through what it looks like when it's just turned on.

Ant

It's a royal PITA with the NECs, as I think the front safety glass goes in from the back of the metal frame, which means you need to take the raw tube out without smashing it.

Trust me on this one, with the questions you're asking, SEND IT TO VDC. THis isn't a newbie procedure to do...

There are newly posted instructions on how to take the tube out on my site below.

This isn't correct. The front glass is just siliconed on the front of the housing.

Just cut off the broken glass (carefully, don't cut yourself, or scratch the tube).

Then replace it with a piece of polycarbonate - from memory Dokworm found that polycarb gave the least halos, better than the stock glass, despite the coating. (I'll confirm that with him).

Antc i have done the same as you for along time, just this week after i changed out my lenses on my marquee for the HD144's I reset the entire projector and started from scratch , before i always set the geometry with only one color on then did the convergence. No mattter what i did i got some banding on my marquee, this time i decided to converge it with all the geometry as is and then did the geometry. WOW what i difference! I even shrunk the image smaller than my screen and just expanded it. Since its sharper in the center of the screen convergence is easier when its all nice and sharp then i just expanded it to my screen size and whala! Nice convergance with hardly any drift now! this also made it alot easier to converge it then to my permanent ceiling mounted marquee for my stack and it has never looked better!

Athanasios

One thing I hate about the NEC is it's a pain in the ass to converge without having a point board. It seems no matter what I do or for how long I can't get it to align nearly as well as I'd like. There is always a chunk of on color off on the grid. I have worked for hours and it just seems hopeless to converge.

Wish I wouldn't have spent $72 on a new C-Drive. This is going to be more expensive than I thought.

It's much, much easier to converge a Plus or an Xtra. And they are newer and less likely to fail. I'd stay well away from a PG these days.

This isn't correct. The front glass is just siliconed on the front of the housing.


Well sonuvagun! I'll check my housing again, I'm sure you're right. THe one I looked at last summer was NOT going to come off the front!:mad:

before i always set the geometry with only one color on then did the convergence. ... this time i decided to converge it with all the geometry as is and then did the geometry. WOW what i difference! Interesting! So you converged B & R to G, and THEN you did the G geometry? I'll have to give that a try when I hang my Marquee again...

I wonder how many projectors this that would work with. ( Converge first then do geometry.)

Bumping this thread...

The front glass on my green tube on my ceiling mounted NEC XG cracked and some glycol leaked out. Since this thread is just about a year and a half old, is all the information the same? I should just remove the tube and send it to VDC?

Also, what would be the best way to remove the tube in order to prevent glycol from leaking onto the boards? Should I try to remove it while it's ceiling mounted or should I take it down and somehow prevent the glycol from leaking onto the boards (suggestions?).

Finally, this set was calibrated by Ken Whitcomb a year ago. How do I make sure the color calibration is not affected?

I suppose I really ought to bleed my 8500 before I re-mount it...... ick


I have never seen a 180DMB22 crack anywhere in 17 years, but err on the safe side if you have the time.


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Bumping this thread...

The green tube on my ceiling mounted NEC XG cracked and some glycol leaked out. Since this thread is just about a year and a half old, is all the information the same? I should just remove the tube and send it to VDC?

Also, what would be the best way to remove the tube in order to prevent glycol from leaking onto the boards? Should I try to remove it while it's ceiling mounted or should I take it down and somehow prevent the glycol from leaking onto the boards (suggestions?).

Finally, this set was calibrated by Ken Whitcomb a year ago. How do I make sure the color calibration is not affected?



I would put down a tarp and try and get it out on the ceiling. Then drop the PJ and retube as normal.

Sorry to say, but a new tube means your colour cal is hosed. You have a HCFR/Calman and can do this yourself right? ;)

I would put down a tarp and try and get it out on the ceiling. Then drop the PJ and retube as normal.

Sorry to say, but a new tube means your colour cal is hosed. You have a HCFR/Calman and can do this yourself right? ;)

I'm not getting a new tube... just sending to VDC to replace the glass. I guess my post wasn't that clear. Just the glass on the front of the tube broke. The tube itself is perfectly fine. VDC still replaces the glass right? I will call them tomorrow I guess...

Oh, sorry, I misunderstood.

Your colour cal will be fine then.


You can DIY it. Just soak it off with turps and you can use a donor tube glass or polycarbonate.

Up to you. Time and effort vs. money.

I have never seen a 180DMB22 crack anywhere in 17 years, but err on the safe side if you have the time.


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I have one... started out looking like scatches and then suddenly !!!!!!:(:(