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From: commgrp@silver.ucs.indiana.edu (BACS Data Communications Group)
Newsgroups: sci.electronics
Subject: Re: IBM monitor repair notes
Message-ID: <55150@iuvax.cs.indiana.edu>
Date: 23 Aug 90 22:05:04 GMT
Sender: daemon@iuvax.cs.indiana.edu
Lines: 17


>Several things cause dim/fuzzy picture, including:
>
>1.  High-time picture tube:  Brightness, contrast and focus may 
>degrade after 10000-15000 hours of use.  Playing with the focus and 
>screen-grid controls can sometimes squeeze a little more useful life 
>from a tube.

BTW, "screen saver" programs which blank the CRT after a preset period 
of inactivity will avoid burning patterns into the phosphor, but will 
NOT extend the ultimate life of the tube:  The filament is on 
constantly, and the hot cathode slowly loses its ability to emit 
electrons.

--

Frank Reid     reid@ucs.indiana.edu