TV repair

busterb · 12-22-2006, 07:14 PM

I have a Toshiba 32" that's 7 years old. It's getting darker as time passes.
I tried this for a living years ago, before I got hungry and quit.

Anyway I looked on back and see no adjustments. I can get a Sams photofact
for about 22 bucks. If I pull back and there's no adjustment, I'll be POed. I'm guessing that I'll have to swap a board out. Somewhere. But I guess the photofact will tell me that.

Guess what I'm asking, anyone have a clue? About the tv and what I'm trying to say.

Hell maybe it's my light going out.

DanaC · 12-22-2006, 07:30 PM

I have absolutely no idea what you just said

xoxoxoBruce · 12-22-2006, 07:34 PM

I do, but don't know the answer.

WabUfvot5 · 12-22-2006, 09:14 PM

You could post at this place and ask. I had that dimming happen to a computer monitor. Ended up finding another so I never figured out what caused the dimming.

Beestie · 12-22-2006, 09:35 PM

If you have a plasma you are done.

Undertoad · 12-23-2006, 12:26 AM

If you receive your signal over the air, all your TVs will be obsolete on February 17, 2009 anyway. That's the date analog TV stops broadcasting, in favor of the new digital TV.

CRT-style TVs are now cheap as hell because they are all going away soon.

skysidhe · 12-23-2006, 02:32 AM

Quote:

Originally Posted by Undertoad

If you receive your signal over the air, all your TVs will be obsolete on February 17, 2009 anyway. That's the date analog TV stops broadcasting, in favor of the new digital TV.

CRT-style TVs are now cheap as hell because they are all going away soon.

Yeah, my son told me the same thing. This is why the cable company gave me a free converter box. Unfortunate for them I ordered satillite tv instead.

WabUfvot5 · 12-23-2006, 02:56 AM

Ja, but will it really switch over? It has been pushed back before. If even 10% of the population doesn't have HD by then there will be a lot of angry people with a lot of time on their hands.

Clodfobble · 12-23-2006, 08:42 AM

Quote:

If you receive your signal over the air, all your TVs will be obsolete on February 17, 2009 anyway. That's the date analog TV stops broadcasting, in favor of the new digital TV.

Seriously?!

Or am I too gullible this morning?

SteveDallas · 12-23-2006, 08:59 AM

No, it's serious... they want everybody to switch to digital TV (which uses a different frequency space) so a) they can stop broadcasting on both frequencies and b) they can sell off the existing analog frequencies to well-heeled corporate interests. But as Jebediah says they've delayed it before--I think the original deadline was 2007 or something like that.

Undertoad · 12-23-2006, 09:06 AM

It's no joke. Turn off your sound and go to dtv.gov. (The site looks like it was done by a 13-year-old; your federal gummit at work.)

Obsolete is a little strong of a word... you will be able to buy converters to get the signal and watch it with an old TV.

Also if you are on cable or satellite these things do not matter to you, it's only over-the-air broadcast that will change.

SteveDallas · 12-23-2006, 09:14 AM

Quote:

Originally Posted by Undertoad

Also if you are on cable or satellite these things do not matter to you

They do if you own your own satellite receiver(s) and you have to run out and buy new ones.... or if the cable company jacks up its rental fees on your converter. (Now, why would they do that?)

glatt · 12-23-2006, 03:30 PM

Quote:

Originally Posted by Undertoad

you will be able to buy converters to get the signal and watch it with an old TV.

.... it's only over-the-air broadcast that will change.

If I have a roof-top antenna strapped to my chimmney, will that stop working well, since the bars will be spaced at the wrong wavelength?

tw · 12-24-2006, 05:34 AM

Quote:

Originally Posted by glatt

If I have a roof-top antenna strapped to my chimmney, will that stop working well, since the bars will be spaced at the wrong wavelength?

HDTV, NTSC and even FM radio are radio signals. Antennas are tuned to radio frequencies with little concern for that signal content.

But digital TV signals are picky. To appreciate the problem, consider a TV with a ghost image. IOW a signal is received directly AND another signal is received by being reflected. Same signal arrives twice - at slightly different times.

So what does the digital TV do? It has two copies of digital information combined in one signal. Which should it use? How does it know which signal to reject? To a TV, the image and its ghost are one digital signal - now confused.

To rush to HDTV, the US decided to implement a first option available - 8-VSB - so as to protect Zenith, the only remaining US TV manufacturer. It was a decision based in politics - not in engineering. As a result, the US standard is different and inferior to standards (COFDM) used in Europe, Japan, Australia, etc. The US standard is less resilient to ghosting meaning that US TV will not operate properly even in moving vehicles.

See the Sinclair Broadcasting lawsuit as a last ditch attempt to implement better standards found elsewhere. Their tests in Baltimore revealed reception of COFDM was better than 8-VSB at two sites and that reception difficulties were due to the presence of strong static signal reflections, or "multipath."

Now for your antenna. HDTV uses the same UHF frequencies of analog TV. An HDTV antenna is simply a better (high gain) UHF antenna to reject more ghosts and to get a stronger signal. High gain means the antenna is more directional. More elements (crossbars) on an antenna create a narrower (higher gain) reception angle.

Ghosting is even why interior antennas don't work well with digital TV. Even the phenomenal bowtie antenna is not very directional - is poor at rejecting ghosts.

So how do you know if a signal is defective? In analog TV, you could see both ghosting and little white dots indicating noise - a loss of signal. But digital TV either compensates for that ghosting or noise, OR you have a stopped image. If signal is lost too long, then it appears as no broadcaster on that frequency (channel).

Cable companies are just licking their chops. Many consumers will give up early on their antenna and finally conceded to more expensive digital cable service.

Current antennas are tuned both to VHF and UHF frequencies. VHF frequencies will be assigned to other services (ie cell phones) in a few years. It was to happen long ago. But HDTV sales were not sufficient. Currently Best Buy and Circuit City are throwing TVs out the door in a price war. Large numbers of new TVs suggests the shutdown of VHF TV channels will occur in 2009. Meanwhile, Zenith is now a foreign manufacturer.

IOW, while analog TV is available, then use that TV to get a good UHF antenna - no ghosts and no little white spots. Then your antenna will be ready for HDTV.

glatt · 12-24-2006, 10:31 AM

Thanks for your reply. I don't fully understand what it all means, but it sounds like I should buy a conversion box and just wait to see if my current antenna works. If it doesn't, then I'll figure it out at that time.

I've currently got a pretty good situation. Both Washington D.C. stations and Baltimore MD stations are in basically the same line of sight from my Arlington VA house. With my (pretty damn old) roof antenna, I pick up about 8 channels clearly, and another 5-8 channels with static. That's more than enough for me. If high gain means a narrower reception angle, then I imagine I'll lose some staions that I currently get, because the transmitters aren't lined up perfectly.

I won't be too happy if this conversion means I'll lose channels that I'm currently getting.

12-22-2006, 07:14 PM	#1
busterb NSABFD Join Date: Jul 2004 Location: MS. usa Posts: 3,908	TV repair I have a Toshiba 32" that's 7 years old. It's getting darker as time passes. I tried this for a living years ago, before I got hungry and quit. Anyway I looked on back and see no adjustments. I can get a Sams photofact for about 22 bucks. If I pull back and there's no adjustment, I'll be POed. I'm guessing that I'll have to swap a board out. Somewhere. But I guess the photofact will tell me that. Guess what I'm asking, anyone have a clue? About the tv and what I'm trying to say. Hell maybe it's my light going out. __________________ I've haven't left very deep footprints in the sands of time. But, boy I've left a bunch.

12-22-2006, 07:34 PM	#3
xoxoxoBruce The future is unwritten Join Date: Oct 2002 Posts: 71,105	I do, but don't know the answer. __________________ The descent of man ~ Nixon, Friedman, Reagan, Trump.

12-22-2006, 09:35 PM	#5
Beestie -◊\|≡·∙■·∙≡\|◊- Join Date: Feb 2003 Location: Parts unknown. Posts: 4,081	If you have a plasma you are done. __________________ ♠ ♥ ♣ ♦

12-22-2006, 07:30 PM	#2
DanaC We have to go back, Kate! Join Date: Apr 2004 Location: Yorkshire Posts: 25,964	I have absolutely no idea what you just said

12-22-2006, 09:14 PM	#4
WabUfvot5 Operations Operative Join Date: May 2002 Posts: 634	You could post at this place and ask. I had that dimming happen to a computer monitor. Ended up finding another so I never figured out what caused the dimming.

12-23-2006, 12:26 AM	#6
Undertoad Radical Centrist Join Date: Jan 2001 Location: Cottage of Prussia Posts: 31,423	If you receive your signal over the air, all your TVs will be obsolete on February 17, 2009 anyway. That's the date analog TV stops broadcasting, in favor of the new digital TV. CRT-style TVs are now cheap as hell because they are all going away soon.

12-23-2006, 02:56 AM	#8
WabUfvot5 Operations Operative Join Date: May 2002 Posts: 634	Ja, but will it really switch over? It has been pushed back before. If even 10% of the population doesn't have HD by then there will be a lot of angry people with a lot of time on their hands.

12-23-2006, 08:59 AM	#10
SteveDallas Your Bartender Join Date: Jan 2002 Location: Philly Burbs, PA Posts: 7,651	No, it's serious... they want everybody to switch to digital TV (which uses a different frequency space) so a) they can stop broadcasting on both frequencies and b) they can sell off the existing analog frequencies to well-heeled corporate interests. But as Jebediah says they've delayed it before--I think the original deadline was 2007 or something like that.

12-23-2006, 09:06 AM	#11
Undertoad Radical Centrist Join Date: Jan 2001 Location: Cottage of Prussia Posts: 31,423	It's no joke. Turn off your sound and go to dtv.gov. (The site looks like it was done by a 13-year-old; your federal gummit at work.) Obsolete is a little strong of a word... you will be able to buy converters to get the signal and watch it with an old TV. Also if you are on cable or satellite these things do not matter to you, it's only over-the-air broadcast that will change.

12-24-2006, 10:31 AM	#15
glatt ™ Join Date: Jul 2003 Location: Arlington, VA Posts: 27,717	Thanks for your reply. I don't fully understand what it all means, but it sounds like I should buy a conversion box and just wait to see if my current antenna works. If it doesn't, then I'll figure it out at that time. I've currently got a pretty good situation. Both Washington D.C. stations and Baltimore MD stations are in basically the same line of sight from my Arlington VA house. With my (pretty damn old) roof antenna, I pick up about 8 channels clearly, and another 5-8 channels with static. That's more than enough for me. If high gain means a narrower reception angle, then I imagine I'll lose some staions that I currently get, because the transmitters aren't lined up perfectly. I won't be too happy if this conversion means I'll lose channels that I'm currently getting.

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