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Glass On Front Of Green Tube Is Cracked

2952 Views 32 Replies 14 Participants Last post by crt nuts, May 14, 2009

MTyson

Discussion Starter · Jan 15, 2008

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

1 - 20 of 33 Posts

Fellenz

· #2 · Jan 15, 2008

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

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nashou66

· #3 · Jan 15, 2008

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

MTyson

Discussion Starter · #4 · Jan 15, 2008

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.

nashou66

· #5 · Jan 15, 2008

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

MTyson

Discussion Starter · #6 · Jan 15, 2008

Quote:
Originally Posted by nashou66 /forum/post/12816458

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.

Doug Baisey

· #7 · Jan 15, 2008

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

Curt Palme

· #8 · Jan 15, 2008

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

Doug Baisey

· #9 · Jan 15, 2008

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

Discussion Starter · #10 · Jan 15, 2008

Quote:
Originally Posted by Doug Baisey /forum/post/12819730

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.

David Cox

· #11 · Jan 15, 2008

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.

Curt Palme

· #12 · Jan 15, 2008

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.

Jesse S

· #13 · Jan 16, 2008

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?

Curt Palme

· #14 · Jan 16, 2008

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.

garyfritz

· #15 · Jan 16, 2008

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

Curt Palme

· #16 · Jan 16, 2008

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

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garyfritz

· #17 · Jan 16, 2008

Gack.

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

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MTyson

Discussion Starter · #18 · Jan 16, 2008

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

Fellenz

· #19 · Jan 16, 2008

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

MTyson

Discussion Starter · #20 · Jan 16, 2008

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.

1 - 20 of 33 Posts

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