Re: Sony KV-25K5U (FE-1) Problem

From: Andy Cuffe (baltimora_at_psu.edu)
Date: 02/07/05 

Date: Mon, 07 Feb 2005 12:14:33 -0500

On Mon, 7 Feb 2005 10:55:28 +0000 (UTC), "Prosonman"
<prosonman@hotmail.com> wrote:

>Hi All,
>
>I'm an electronics engineer but know very little about T.V repair and was
>hoping someone out there may be able to point me in the right direction to
>fixing a problem with my T.V.
>
>The problem or problems may be connected, firstly the picture quality has
>become quite poor, in that it is no longer a sharp picture but I would say
>out of focus particularly on the sides. This is very apparent on writing on
>the screen that is virtually illegible and appears to have like a red
>ghosting effect on every letter.
>
>The other problem is a brightness problem, it may sound obvious but it gets
>brighter when the image on screen has a lot of white in it, even the writing
>on screen becomes clearer. For example on a news channel there is a band at
>the bottom of the screen giving information, most of the time I find this
>hard to read but when the picture above goes to a nice bright outdoor scene
>suddenly the writing becomes legible, not perfect but at least I can be read
>it.
>
>The T.V is a Sony KV-25K5U that I believe is also called an FE-1, I don't
>know if the problem is a faulty tube, a poor HT or bad power supply. Any
>help would be greatly appreciated and where to get circuit diagrams would be
>helpful.
>
>
>Many thanks
>Richard.
>

It sounds like the CRT is getting weak. I've seen a lot of Sony TVs
with weak CRTs that get sharper and brighter (ususally also tinted one
color) when displaying a mostly white screen. I'm not sure what
causes that odd effect, but I've only seen it on sets with weak CRTs.
You may be able to improve the picture by adjusting the focus control
on the flyback, or CRT neck board.
Andy Cuffe

baltimora@psu.edu <-- Use this email address first

acuffe@gmail.com

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