Re: TV Picture Symptom

Tov wrote:
On Dec 19, 9:07 pm, none <""doug\"@(none)"> wrote:
Tov wrote:
On Dec 19, 6:56 pm, none <""doug\"@(none)"> wrote:
Sam Goldwasser wrote:
"James Sweet" <jamessw...@xxxxxxxxxxx> writes:
<bruce.get...@xxxxxxxxx> wrote in message
news:d15304bf-c767-4b13-b298-6202587a673f@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Hi,
I have a chance to pick up a nice 32" TV for free. Not sure of the
brand or model yet, but the owner says it only displays 3/4 of the
picture until the set warms up for 5 minutes, then it's fine until
shut down.
What would typically cause this and is it a fairly easy repair? I
have soldering skills, etc. but am not a tech.
Thanks.
Bad capacitors in the vertical section, you don't really need any special
tools, just replace all the suspects, it'll only cost a few dollars. This is
a good candidate for a beginner learning to repair TVs.
Agreed. But make sure you understand and follow the SAFETY guidelines.
Service information will also help to identify the suspect parts.
Your local large public library may get the Sams' Photofacts.
--- sam | Sci.Electronics.Repair FAQ:http://www.repairfaq.org/
Repair | Main Table of Contents:http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ:http://www.repairfaq.org/sam/lasersam.htm
| Mirror Sites:http://www.repairfaq.org/REPAIR/F_mirror.html
Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.
If you are very careful, you can narrow your search area by using a heat
gun on the capacitors and it will be obvious which capacitor is at
fault.
How exactly will it be obvious?
If the picture is restored to normal when the set heats up, heating
the failing capacitor will restore the picture height. Conversely,
cooling it will make the picture shrink.

Interesting. But presumably this method only works for warm-up
problems and cannot be adapted to failing capacitors in general?
It is a bit more general than that but is not universal. If a part has
completely failed, heating or cooling do not change how it works. But
failing parts often change characteristics when heated. Heat guns and
freeze mist have long been used for this kind of troubleshooting. It
just means you should start troubleshooting when things first start
going bad rather than waiting until you have a complete failure.
.

Relevant Pages

  • Re: TV Picture Symptom
    ... What would typically cause this and is it a fairly easy repair? ... Bad capacitors in the vertical section, you don't really need any special ... ignored unless my full name AND either lasers or electronics is included in the ... If the picture is restored to normal when the set heats up, ...
    (sci.electronics.repair)
  • Re: 20 year old Sony KV-25XBR
    ... I am sure that because of the age of the set, ... capacitors that have become high in ESR. ... The problem that developed today is that the picture is well, ... The question is whether or not it's worth repairing or to trash it. ...
    (sci.electronics.repair)
  • Re: Panasonic CRT Picture - missing and/or shifted
    ... Very common to have capacitors in the power supply and the scan ... primarily for GameCube and for the occasional video. ... so that we're missing about 10% of the right side of the picture. ...
    (sci.electronics.repair)
  • Re: Why do some manufacturers wrap the electrolytic capacitor that gets the hottest in a switching p
    ... part to fail in their units. ... include the operating temperature. ... If you're shopping for a conspiracy theory, I guess the capacitors are ... badly specified or picking up heat from adjacent heat dissipating ...
    (sci.electronics.repair)
  • Re: Problem with vertical sweep on Toshiba CF2665K TV Set
    ... over 20 years and was discouraged to find no linearity adjustment pot. ... > I replaced all electrolytic capacitors Cxxx I could find. ... It is now about half the size of a normal picture, ...
    (sci.electronics.repair)