CRT fungus removal ("cataracts")

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jonb
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CRT fungus removal ("cataracts")

Post by jonb » Fri Oct 12, 2018 1:51 pm

I've got a CRT here with bad fungus between the tube and safety glass layer. There are various videos on tut'net that show how to prise the protective glass off the screen using a heat gun and scraper, then clean and reassemble. Yet this screen is a bit different as it has a mounting frame that wraps around the front of the tube, preventing me from removing the safety glass and the glue underneath.

bezel.jpg

The frame appears to have been bonded to the screen using potting compound.

compound.jpg

It looks black but under the coating it's white and quite hard. I haven't tried to heat it other than to stab it with an iron at 350C and it hasn't really reacted.

compound scratched.jpg

Does anyone know what it might be, and whether the bezel can be safely removed in one piece?

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jonb
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Re: CRT fungus removal ("cataracts")

Post by jonb » Fri Oct 12, 2018 2:36 pm

I have to say, I'm not too sure about this. I read on Herb Johnson's web site that the frame is a part of the CRT's implosion protection and shouldn't be removed. I might be able to grind the curved bezel part off the frame, though, or break the safety glass (carefully) and remove it piecemeal?

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vanpeebles
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Re: CRT fungus removal ("cataracts")

Post by vanpeebles » Fri Oct 12, 2018 6:22 pm

I think a danger Will Robinson Robbie the robot animated gif meme would be most appropriate here! :shock:

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jonb
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Re: CRT fungus removal ("cataracts")

Post by jonb » Fri Oct 12, 2018 8:12 pm

IMG_1155.GIF
Warning! Warning! DANGER WILL ROBINSON,

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daveejhitchins
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Re: CRT fungus removal ("cataracts")

Post by daveejhitchins » Sat Oct 13, 2018 6:17 am

I think it’s on with the safety gear and out with the Dremel! After doing the Yoga to steady the hands - maybe have someone with you too!

Dave H :D
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guesser
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Re: CRT fungus removal ("cataracts")

Post by guesser » Sat Oct 13, 2018 7:52 am

Where would you get a new one to replace the mutilated one? How would you bond it on?

Seems like a non-user-servicable part to me :shock:
A web based teletext editor which can export as Mode 7 screen memory: https://zxnet.co.uk/teletext/editor

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Re: CRT fungus removal ("cataracts")

Post by daveejhitchins » Sat Oct 13, 2018 8:09 am

Once you’ve managed separate the two pieces, it’s a case of cleaning up and then re gluing them together. I’ve one waiting for me to do, from my Rarther Large , I think, HP68000 (?)

Dave H :D

Edit: I wan’t thinking of using the Dremel on the screen, just the outer casing.
Last edited by daveejhitchins on Sat Oct 13, 2018 8:12 am, edited 1 time in total.
Parts: UM6502CE, GAL22V10D, GAL16V8D, AS6C62256A, TC514400AZ, WD1772, R6522, TMS27C512, AT28C256
Products: ARA II, ARA III, ABR, ATI, AP6, MGC, AP5 . . .
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Re: CRT fungus removal ("cataracts")

Post by sbadger » Sat Oct 13, 2018 8:22 am

I was waiting for Dave to say, just put it in the dishwasher....

I'm a bit disappointed! :wink:
So many projects, so little time...

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Re: CRT fungus removal ("cataracts")

Post by daveejhitchins » Sat Oct 13, 2018 8:35 am

sbadger wrote:
Sat Oct 13, 2018 8:22 am
I was waiting for Dave to say, just put it in the dishwasher....

I'm a bit disappointed! :wink:
Missed opertunaties #-o

Dave H :D
Parts: UM6502CE, GAL22V10D, GAL16V8D, AS6C62256A, TC514400AZ, WD1772, R6522, TMS27C512, AT28C256
Products: ARA II, ARA III, ABR, ATI, AP6, MGC, AP5 . . .
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Elminster
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Re: CRT fungus removal ("cataracts")

Post by Elminster » Sat Oct 13, 2018 8:49 am

Dishwashers are good for cleaning indoor climbing holds when you swap them over as well. Perhaps time for a ‘what do you put in your dishwasher?’ thread,

I think we need a full hd video of Jon (or Dave) Dremelling a monitor in hazmat gear.

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Re: CRT fungus removal ("cataracts")

Post by vanpeebles » Sat Oct 13, 2018 12:35 pm

vanpeebles wrote:
Fri Oct 12, 2018 6:22 pm
I think a danger Will Robinson Robbie the robot animated gif meme would be most appropriate here! :shock:
lol that's the one! I'll offer to help by standing in the corner with my back turned and my hands over my ears, while holding this expression >_<

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jonb
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Re: CRT fungus removal ("cataracts")

Post by jonb » Sat Oct 13, 2018 2:30 pm

Oh ye of little faith!

IMG_4961.jpg
Frame cut off
.
.
IMG_4959.jpg
Close up 1
.
.
IMG_4958.jpg
Close up 2 - not too neat.
.
.
IMG_4960.jpg
Screen protector
.
.
MDS rides again.JPG
What it looked like before
.
.
IMG_4963.jpg
What it looks like now
.
.
So it's true: Who dares, wins!
Last edited by jonb on Sat Oct 13, 2018 2:32 pm, edited 2 times in total.

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Elminster
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Re: CRT fungus removal ("cataracts")

Post by Elminster » Sat Oct 13, 2018 2:34 pm

Disappointed no pictures of you and Robbie in hazmat suits.


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jonb
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Re: CRT fungus removal ("cataracts")

Post by jonb » Sat Oct 13, 2018 3:36 pm

And following a week or two of the usual diagnostics and otherwise mucking about..
MDS OS up.jpg
Intel ISIS-II v4.0 operating system

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Re: CRT fungus removal ("cataracts")

Post by jonb » Sat Oct 13, 2018 4:58 pm

Oh, go on... one more shot.
dir listing.jpeg

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leenew
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Re: CRT fungus removal ("cataracts")

Post by leenew » Sat Oct 13, 2018 5:13 pm

Good work!
Glad to see you keep a fire extinguisher on standby...

Lee.

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vanpeebles
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Re: CRT fungus removal ("cataracts")

Post by vanpeebles » Sat Oct 13, 2018 5:35 pm

leenew wrote:
Sat Oct 13, 2018 5:13 pm
Good work!
Glad to see you keep a fire extinguisher on standby...

Lee.
A pair of clean underpants in a glass case would of been more appropriate :lol:

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1024MAK
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Re: CRT fungus removal ("cataracts")

Post by 1024MAK » Sun Oct 14, 2018 2:07 am

Two things...
It’s not a very good “screen protector” if it can’t even keep mould out...!
I’m disappointed that the big white power button does not light up...

Mark

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Re: CRT fungus removal ("cataracts")

Post by daveejhitchins » Sun Oct 14, 2018 6:53 am

1024MAK wrote:
Sun Oct 14, 2018 2:07 am
Two things...
It’s not a very good “screen protector” if it can’t even keep mould out...!
I’m disappointed that the big white power button does not light up...

Mark
It's the glue that goes mouldy! But you knew that . . .

Dave H :D
Parts: UM6502CE, GAL22V10D, GAL16V8D, AS6C62256A, TC514400AZ, WD1772, R6522, TMS27C512, AT28C256
Products: ARA II, ARA III, ABR, ATI, AP6, MGC, AP5 . . .
For a price list, contact me at: Retro Hardware AT dave ej hitchins DOT plus DOT com

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1024MAK
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Re: CRT fungus removal ("cataracts")

Post by 1024MAK » Sun Oct 14, 2018 10:37 am

daveejhitchins wrote:
Sun Oct 14, 2018 6:53 am
1024MAK wrote:
Sun Oct 14, 2018 2:07 am
Two things...
It’s not a very good “screen protector” if it can’t even keep mould out...!
I’m disappointed that the big white power button does not light up...

Mark
It's the glue that goes mouldy! But you knew that . . .

Dave H :D
Oi! Someone’s cut a link in the chain that I was yanking! :shock: :lol: :mrgreen:

Mark

PS three edits (so far) as it’s very distracting trying to type in a reply while one of our dogs destroys a biscuit packet an inch away from the touch screen device i’m writing this on!
Last edited by 1024MAK on Sun Oct 14, 2018 10:39 am, edited 2 times in total.

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Elminster
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Re: CRT fungus removal ("cataracts")

Post by Elminster » Sun Oct 14, 2018 11:55 am

Glue it back together with CT1. Anti mould and comes in many colours! Use it all the time, not usually in a retro computing context I must admit :twisted:

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jonb
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Re: CRT fungus removal ("cataracts")

Post by jonb » Sun Oct 14, 2018 4:21 pm

1024MAK wrote:
Sun Oct 14, 2018 2:07 am
I’m disappointed that the big white power button does not light up...
It does, but the bulb has gone. It's a very odd shaped little thing, but I managed to find one so I'll be ordering it soon. 25VAC.
Elminster wrote: I think we need a full hd video of Jon (or Dave) Dremelling a monitor in hazmat gear.
The cutting disks on the Dremel were great but wore out too soon, so I had to go nuclear and use the angle grinder to finish the job. Scary.

No, you don't need a video of me in my hazmat gear.. Garage overalls make me look like that bloke Minty from Eastenders - basically I'm too fat to carry that look off. Scarier. :shock:
Last edited by jonb on Sun Oct 14, 2018 4:22 pm, edited 1 time in total.

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Elminster
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Re: CRT fungus removal ("cataracts")

Post by Elminster » Sun Oct 14, 2018 4:53 pm

A garage mechanic having at a monitor with a industrial angle grinder image in my head now.

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