Sponsor Message:
Non Aviation Forum
My Starred Topics | Profile | New Topic | Forum Index | Help | Search 
TV Tech Problem: Advice Needed  
User currently offlineRNOcommctr From United States of America, joined Jan 2001, 830 posts, RR: 3
Posted (8 years 3 months 2 weeks 2 days 21 hours ago) and read 3068 times:

I am getting a new TV today because of the following problem with my existing 27-inch Sharp tube-type set (15 years old but used very little). When I turn the TV on, just a thin horizontal line of picture appears. This condition remains for maybe 30 to 45 minutes before the full picture finally comes on.

I hate to trash the thing because it eventually gets a great picture. I would love to give the set to a charity or even a little mom-and-pop repair shop to fix it and sell it.

Anyone have idea what the problem might be and would it be feasible for someone to fix it?

Thanks.


Active loading only, ma'am, keep it moving!
11 replies: All unread, jump to last
 
User currently offlineAsstChiefMark From , joined Dec 1969, posts, RR:
Reply 1, posted (8 years 3 months 2 weeks 2 days 20 hours ago) and read 3062 times:

After the TV has been unplugged for a few hours, remove the rear cover. Blow out all the dust with a can of that compressed air that's used to blow dust out of computers. Do a thorough job of cleaning the picture tube connections and high voltage board. Sometimes dust buildup can create small shorts that mimic larger problems. Often, once the dust is removed, the TV will work normally.

Mark


User currently offlineOly720man From United Kingdom, joined May 2004, 6843 posts, RR: 11
Reply 2, posted (8 years 3 months 2 weeks 2 days 20 hours ago) and read 3058 times:

Beware that the high voltages can be lethal, so you may want to use some earthing strips to make sure any capacitors are fully discharged.

More than a few hours may be needed for self discharge. Our lab manager was rather unpleasantly surprised to still find high voltages on a tv more than a day after it was unplugged.



wheat and dairy can screw up your brain
User currently offlineKaiGywer From United States of America, joined Oct 2003, 12281 posts, RR: 35
Reply 3, posted (8 years 3 months 2 weeks 2 days 20 hours ago) and read 3054 times:
AIRLINERS.NET CREW
FORUM MODERATOR

Quoting Oly720man (Reply 2):
Beware that the high voltages can be lethal, so you may want to use some earthing strips to make sure any capacitors are fully discharged.

More than a few hours may be needed for self discharge. Our lab manager was rather unpleasantly surprised to still find high voltages on a tv more than a day after it was unplugged.

Yeah, the best is to not touch anything in the TV, but rather use the compressed air. If you have to touch anything in the TV, use only one hand. That way, should you get zapped, the current will only go through your hand, and not your body (including heart).

If cleaning it doesn't work, I'm afraid the TV is probably not worth saving, as new TVs are so cheap these days.



“Once you have tasted flight, you will forever walk the earth with your eyes turned skyward, for there you have been, an
User currently offlineRNOcommctr From United States of America, joined Jan 2001, 830 posts, RR: 3
Reply 4, posted (8 years 3 months 2 weeks 2 days 19 hours ago) and read 3047 times:

I am scared to death of electricity, so I will take all this advice very seriously. I'll give the thing a week to discharge and will just use the compressed air.

Thanks so much for the help.



Active loading only, ma'am, keep it moving!
User currently offlineAeroWesty From United States of America, joined Oct 2004, 20822 posts, RR: 62
Reply 5, posted (8 years 3 months 2 weeks 2 days 19 hours ago) and read 3042 times:

While all the above is good advice, I have to wonder about something. In the past couple of decades, all TVs have been built with an "instant-on" feature that even when the TV is unplugged, will burn the equivalent of about a 25-watt bulb to keep the picture tube alive enough so we don't have to wait for it to warm up like in the olden days. Anyone remember waiting a minute or so for the old B&W consoles to come to life?

I wonder if this has anything to do with your problems.



International Homo of Mystery
User currently offlineKmh1956 From Bermuda, joined Jun 2005, 3324 posts, RR: 7
Reply 6, posted (8 years 3 months 2 weeks 2 days 19 hours ago) and read 3040 times:

Quoting AeroWesty (Reply 5):
Anyone remember waiting a minute or so for the old B&W consoles to come to life?

Not only that, I remember the little white dot that appeared when you turned the set off and stayed for a good minute or so.



'Somebody tell me why I'm on my own if there's a soulmate for everyone' :Natasha Bedingfield
User currently offlineRichardnhsv From United States of America, joined Apr 2005, 473 posts, RR: 2
Reply 7, posted (8 years 3 months 2 weeks 2 days 17 hours ago) and read 3027 times:

If this is what you mean...


It's called vertical collapse. Get a new TV..."fault with the vertical deflection circuitry. Many causes, dry joints, elecrolytic capacitors, vertical output , vertical oscillator etc."

Source: http://www.overclockers.com.au/wiki/TV_/_Monitor_/_Fault_Diagnosis



"If you've ever had a filet this good, welcome back." - Ruth Fertel
User currently offlineRNOcommctr From United States of America, joined Jan 2001, 830 posts, RR: 3
Reply 8, posted (8 years 3 months 2 weeks 2 days 16 hours ago) and read 3014 times:

Vertical collapse... that is what I do after about eight beers!

Yes, that is exactly what my old TV looks like. Thanks.



Active loading only, ma'am, keep it moving!
User currently offlineHAWK21M From India, joined Jan 2001, 31712 posts, RR: 56
Reply 9, posted (8 years 3 months 2 weeks 2 days 1 hour ago) and read 2995 times:

Vertical hold defect.
If you know the circuitry there would be a Variable resister try tuning that with a Screwdriver.Else call the Expert.
Dont touch the Transformers/capicators.
regds
MEL



Think of the brighter side!
User currently offlineSprout5199 From United States of America, joined Feb 2005, 1855 posts, RR: 2
Reply 10, posted (8 years 3 months 2 weeks 1 day 23 hours ago) and read 2987 times:

Quoting Oly720man (Reply 2):
More than a few hours may be needed for self discharge. Our lab manager was rather unpleasantly surprised to still find high voltages on a tv more than a day after it was unplugged

If the bleeder resistor is bad it will stay charged for a long time.

Quoting RNOcommctr (Reply 4):
I am scared to death of electricity, so I will take all this advice very seriously. I'll give the thing a week to discharge and will just use the compressed air.

If You have no electronic experience, then I would say DONT OPEN IT AT ALL. take it to a shop or buy a new one. I have been in electronics for 20 years(damn Im old) and I still hate working on crt's(cathode-ray tubes--tv's). have been bit by them too many times. 30kv sucks

Dan in Jupiter


User currently offlineRNOcommctr From United States of America, joined Jan 2001, 830 posts, RR: 3
Reply 11, posted (8 years 3 months 2 weeks 1 day 21 hours ago) and read 2974 times:

I went ahead and bought a 27-inch Sony flat-screen (CRT) last night. I am really happy with it... nothing fancy, but it has a great picture and is fine for the small amount of news and baseball I watch.

My buddy got at the same time a 34-inch Sony widescreen. It replaces a 36-inch Toshiba he had. The picture on the widescreen sure looks small compared to his old 36-inch, plus it appears flattened out. Anyway, we are both happy with our new sets although my back is feeling the effects of the effort last night.

The old TV you guys so kindly commented on yesterday goes to a charity and I will let their electronics expert tackle the problem. Thanks again for the help.



Active loading only, ma'am, keep it moving!
Top Of Page
Forum Index

This topic is archived and can not be replied to any more.

Printer friendly format

Similar topics:More similar topics...
Language Immersion Schools: Advice Needed! posted Thu Sep 14 2006 06:32:14 by Tsaord
Cooking Advice Needed: Flat-iron Steaks posted Sun Jul 30 2006 23:58:40 by DesertJets
Cruise Advice Needed.. posted Sun Jun 18 2006 05:26:47 by STT757
Hurghada, Egypt. Advice Needed. posted Tue Jun 6 2006 17:02:53 by HBDAN
Approach To Hamilton Island Airport: Advice Needed posted Sun Jun 4 2006 19:52:28 by PlaneHunter
Dating Advice Needed posted Thu May 18 2006 02:56:44 by BristolFlyer
Advice Needed For An Alcohol Related Ticket I Got. posted Sat Apr 22 2006 09:24:20 by Joness0154
Trip To UK [LON/BHX/MAN]--Advice Needed posted Sun Apr 16 2006 22:17:15 by Karan69
Advice Needed: What Cell Phone To Buy posted Thu Mar 9 2006 17:44:28 by Tu204
Bangkok Travel Advice Needed posted Mon Mar 6 2006 14:20:00 by Zarniwoop