Sanyo 1994 TV, blooming?


  #1  
Old 05-08-01, 08:47 PM
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I am having a problem with the picture on my TV. I seems to happen more the longer I have the TV on. I was looking for some answers in other postings, and I think my picture is blooming. Is blooming when the picture shrinks in on the top and sides and then returns to normal? Also, anything white or really red makes this happen. Is my TV dying a slow death or what? Help.
 
  #2  
Old 05-09-01, 07:49 AM
Smokey
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Good Morning, drgnman:

It would have been beneficial to know the type of set and approximate age of the unit. It gives a little clearer picture of the problem.

Generally speaking speaking, however, my thought would be a problem with the high voltage regulation. Consider that the picture tube is just a simple vacuum tube in concept. The tube requires anywhere between 25,000 and 45,000 volts on the screen. When the screen is black, the high voltage has tendency to rise. When pictures with large areas of white (or red) appear, the voltage tends to decrease because of the added current through the electron guns (cathodes).

The sets are all configured with a circuit to regulate this high voltage so that it maintains a preset value. This prevents shrinkage or blooming of the picture during brightness level changes. Most of the better quality sets have a circuit designed so that a failure of high voltage regulation will cause the picture to become unstable horizontally or vertically. This is to frustrate you enough to turn the set off and get help....and to prevent the set from catching fire.

My best advice is not to run the set until this high voltage circuit is repaired. Unregulated, the high voltage can reach values around 55,000 volts. A simple arc or insulation breakdown internally can (and often does) cause fires.

Smokey
 
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Old 05-09-01, 09:43 AM
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Hi Smokey,

One more question.......Is this worth repairing? Its a Sanyo 1994 and I don't know from models. The cost of a new TV is about $350 - $500 CDN.
 
  #4  
Old 05-09-01, 01:48 PM
Smokey
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Good Afternoon, drgnman:

Speaking from experience, I would answer no. The costs of repairs these days (if you can find someone to work on it) would easily mount up until it would be far more than the set is actually worth. And, when you get it fixed, you still have a seven year old set that may face further failures down line. Some of these shops are charging $125 an hour (and up).

Second train of thought: television as we know it will soon be obsolete. The entire industry is going to change over to high definition television (HDTV). Television will no longer be broadcast from huge towers within your city. Everything will be cable or satellite. No more roof antennae.

Since you are considering a new set, it is wise to think of a set that HDTV compatible.

Smokey
 
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Old 05-09-01, 02:03 PM
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Hi Smokey

Thank you very much for the information. It was very helpful.
 
  #6  
Old 05-10-01, 08:19 AM
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Come back and visit anytime.
 
 

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