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From: kawaguch@nunki.usc.edu (Atsushi Kawaguchi)
Newsgroups: sci.electronics
Subject: Re: Cable TV Descramblers - general questions
Message-ID: <7466@chaph.usc.edu>
Date: 18 Jan 90 09:44:53 GMT
References: <1753@pbhyc.PacBell.COM>
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In article <1753@pbhyc.PacBell.COM> rms@PacBell.COM (Rob Santello) writes:
>Sorry if this is an old topic...
>I have a couple of general questions about the 'standard' cable box. After
>removing the cover of mine to look inside, I noticed an interlock switch
>which sure enough was tripped when opened. 

>So - is that interlock really some kind of anti-tampering switch? Is

Long time ago, I used to work at Pioneer, making cable converter boxes
for a cable company called Qube.  Anyway, the box had a sort of self-
destruction mechanism.  First, the box can be opened only by removing one
screw through a small opening, which has an elliptical head, requiring special
tool to unscrew it.  Next, there is a mechanical switch inconspicuously
located, which flips if the cover is opened.  If the box is powered on
without resetting this switch, the fuse will be blown, making the box useless.
Of course, the serviceperson knows about this, but average user do not.
Since they had a device like that ten years ago, the modern cable boxes must
have far more sophisticated methods to detect tampering of box by the user.

U   U SSSS CCCC Atsushi Jun Kawaguchi
U   US    C     INTERNET: kawaguch@girtab.usc.edu
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