Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.1 Fluke 1/4/84; site fluke.UUCP
Path: utzoo!watmath!clyde!floyd!harpo!decvax!ucbvax!ucbcad!tektronix!uw-beaver!ssc-vax!fluke!pwl
From: pwl@fluke.UUCP (Paul Lutt)
Newsgroups: net.micro.pc
Subject: Re: Repairs
Message-ID: <550@vax1.fluke.UUCP>
Date: Mon, 19-Mar-84 10:59:40 EST
Article-I.D.: vax1.550
Posted: Mon Mar 19 10:59:40 1984
Date-Received: Thu, 22-Mar-84 00:43:59 EST
References: <17494@sri-arpa.UUCP>
Organization: John Fluke Mfg. Co., Everett, WA
Lines: 21


     It has been suggested in this group that the IBM monitor could be
repaired by any competent TV service type.  While this is possibly true,
it should be noted that the IBM monochrome monitor runs at 18 kilohertz,
not the more usual 15,750 used in all normal NTSC compatible televisions.
Replacing the IBM monitor's flyback transformer with one from a normal TV
would most likely burn out the horizontal drive system.  This is because
flyback systems in CRT systems are highly tuned.  Using a component designed
for a different operating frequency from the one originally installed will
unbalance this tuning, causing excessive power consumption and overstressing
of drive components.

     The modern CRT is a marvel of design, but it must be kept in mind that
just because the tube sitting on your computer LOOKS like a normal television
doesn't mean that it is necessary the same.  Find out what you have before
you attempt to repair it.

Paul Lutt
John Fluke Mfg. Co., Inc.
Everett, WA
{uw-beaver,decvax!microsof,ucbvax!lbl-csam,allegra,ssc-vax}!fluke!pwl