68kMLA Classic Interface

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Removing CRT Neck Board Glue
Posted by: Garrett on 2020-10-04 14:48:34
Strange question today...

I found someone who can recap my Classic's analog board. I noticed there is a little bit of hot glue keeping the neck board connected to the CRT base. They suggested I could use some rubbing alcohol to dissolve the hot glue, so I don't have to worry about using a box cutting knife to cut through the glue. Does this work well? Could it damage anything? 

I'm assuming I just take a cotton swab or Q-tip and douse it in the rubbing alcohol, then rub it on the glue?

When removing the neck board, should it just pull on off?



Posted by: bibilit on 2020-10-04 15:11:52
the glue is not very strong, no need to cut or do anything.

Posted by: Garrett on 2020-10-05 04:12:46
the glue is not very strong, no need to cut or do anything.
I've heard people mention that you should cut the glue. I even noticed in the service manual for the Classic/C II that it says you need to cut the glue using a craft knife.

But, then again, I'm guessing after 29 years the glue probably isn't nearly as strong as it was when new. So I should just be able to pull straight up on the neck board and it should disconnect from the CRT base? I obviously don't want to damage anything or break the CRT.

Posted by: bibilit on 2020-10-05 04:39:06
Yes, never had an issue. 

Posted by: jessenator on 2020-10-05 05:35:08
Just be sure to keep the motion of the neckboard perpendicular to the neck connector as you remove it, so you don't shatter the fragile "nipple" on the end of the tube. If you're worried, there's probably no harm in running a warm hair dryer over it to soften the glue a little bit. The metal contacts of the tube encircle the "nipple" so using an exacto flat against the glue blob should be just fine. Just don't use the point. 

Posted by: Garrett on 2020-10-05 10:15:41
Just be sure to keep the motion of the neckboard perpendicular to the neck connector as you remove it, so you don't shatter the fragile "nipple" on the end of the tube.
My main worry is accidentally breaking the nipple on the tube. I just pull straight up on the neck board, correct?

Posted by: LaPorta on 2020-10-05 10:20:00
Straight off. There is literally wiggle room to keep pressure on both sides of the board, pulling rearward, and wiggle back and forth slightly to slide it off. The Nipple is smaller than the hole it fits into, it isn't a snug fit.

Posted by: rplacd on 2020-10-05 10:20:16
My main worry is accidentally breaking the nipple on the tube. I just pull straight up on the neck board, correct?


Truth be told, I'd be even more careful about pulling perpendicular to the neck board... I've ruined a 9" CRT by accidentally whacking the CRT neck from the bottom, when trying to disconnect a SCSI cable. That ending up shattering the nipple anyway. (Actually, @jessenator sold me a replacement CRT!) Maybe, if it's hot melt glue, you could ease it off with IPA + a craft knife?

Posted by: LaPorta on 2020-10-05 10:21:31
I busted one 20 years ago in high school. Never was cavalier again.

Posted by: Garrett on 2020-10-05 10:32:04
The Nipple is smaller than the hole it fits into, it isn't a snug fit.
So, if I'm understanding this correctly, it shouldn't take much force at all to remove the board? I guess I'm not understanding the "keep motion perpendicular to the neck board" part - you just pull straight up on the board, right? Do you need to wiggle back and forth slightly, or can you just pull off? I may try to cut as close to the plastic connector as possible, if needed.

Maybe I'm making a mountain out of a mole hill? It's just the CRT in this machine is in pretty good condition, so the last thing I want to do is accidentally destroy it.

Posted by: erichelgeson on 2020-10-05 10:43:55
Sometimes seeing it in action answers a lot of questions. Hopefully this helps:



View attachment PXL_20201006_014540864.mp4
Posted by: Garrett on 2020-10-05 11:07:24
Thanks, @erichelgeson. The video helped a lot. When replacing the board, do you feel when the board is completely on?

Posted by: erichelgeson on 2020-10-05 11:15:08
Yes you feel it seat. Don't have to push hard just firm till you feel it.

Posted by: Garrett on 2020-10-08 09:52:24
I got the analog board removed from the computer. I tried the alcohol method, and it seemed to work. I was able to get the neck board removed without any problems.

The real pain was actually the anode cap on the side of the CRT. It took a good 10-15 minutes for me to get it removed. I hope it goes back in much simpler.

Here's more: 



Thanks to everyone for your input. It is greatly appreciated. And thanks Eric for that video.

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