Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!cwjcc!hal!nic.MR.NET!tank!ncar!noao!asuvax!anasaz!john
From: john@anasaz.UUCP (John Moore)
Newsgroups: sci.electronics
Subject: Re: RCA TV question
Summary: probably the focus divider
Message-ID: <1403@anasaz.UUCP>
Date: 20 Oct 88 16:25:40 GMT
References: <952@aluxz.UUCP>
Reply-To: john@anasaz.UUCP (John Moore)
Organization: Anasazi Inc, Phoenix AZ
Lines: 30

In article <952@aluxz.UUCP> ndp@aluxz.UUCP (Nimesh Parikh) writes:
>
]I have an old RCA tv set (~8 years) which just went bad.
]
]Here is what happened. The tv went out of focus one day
]so I used the knob in the back to bring it back in focus.
]This worked great for about 2-3 weeks. Suddenly one day,
]while I was watching it, it just blurred right in front of
]my eyes. Now the back knob has no effect.
]
]Did the picture tube quit ? or would it be just some
]component (R or C) inside which gave in after long time
]of service ? Should I just throw the tv away or what ?

I just had this same problem on a 15 year old Sears TV. The
problem was solved by replacing the focus divider.

The focus voltage is derived from the anode voltage using
a large and strangely built resistor called the focus divider.
On my set, it was about 3x4x1 inches, made of plastic and filled
with potting material, and mounted on the side of the high
voltage section. It had one wire to the neck of the picture tube
(to the focus electrodes), one to the high voltage, and one to
the top of the focus adjustment pot. Replacing this part (~$15)
will probably solve your problem.
-- 
John Moore (NJ7E)           {decvax, ncar, ihnp4}!noao!nud!anasaz!john
(602) 861-7607 (day or eve) {gatech, ames, rutgers}!ncar!...
The opinions expressed here are obviously not mine, so they must be
someone else's. :-)