Extreme screen "rot" on an ADM-3a (an ebay auction)

Mike Loewen mloewen at cpumagic.scol.pa.us
Thu Jul 17 09:26:23 CDT 2008


On Thu, 17 Jul 2008, Mr Ian Primus wrote:

> middle. It's referred to as "cataracts". I don't know if it's mold, but 
> it basically results in the breakdown of the PVA bonding compound that 
> holds the safety glass to the face of the tube. To remove it, at least 
> on the TV tubes, you take the the tube out of the set, put it neck down 
> in a large bucket/barrel so that it's supported, and use a heat gun to 
> heat up the screen. After a while, the PVA will soften, and the 
> faceplate can be gently separated from the tube. Don't pry it up - try 
> to gently induce air bubbles under it with wooden shims and heat. Once 
> the bond breaks over most of the tube, the glass should come off without 
> breaking. Then you clean out all the PVA gunk, and reattach the safety 
> glass with packing tape along the edges.

    I have a HP 2647A terminal with a severe case of screen rot which I 
would like to refurbish:

http://sturgeon.css.psu.edu/~mloewen/Oldtech/Terminals/HP2647A-1L.jpg
http://sturgeon.css.psu.edu/~mloewen/Oldtech/Terminals/

    Do you think this would be a candidate for the heat gun method, or 
acetone around the edges of the shield as others have suggested?


Mike Loewen				mloewen at cpumagic.scol.pa.us
Old Technology	http://sturgeon.css.psu.edu/~mloewen/Oldtech/



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