Hi Justine,

I have assembled a simple 115v SMPS using STR50115. the components are less and easy to assemble, The circuit gives 115v for B+ and 14v only, 7v was tapped from the 14v point using 7808 power regulator, fly back pulse is feed to pin No2 of the IC, the TV is working quite satisfactorily.

I still wonder why the original power supply failed despite my best efforts , a very detailed study is required to know the actual cause,

I thank you again for the time and patience you had to answer my quiries

with warm regards

Abraham

HI Abraham,

Congrat on your successful repair. The 7808 should produce 8 volt and not 7 volt. a 7807 will produce 7 volt. Actually there are some ready made power supply module from China to cater for such problem where the original power supply can’t be repaired. There is one more factor why a power supply still not functioning-components breaking down when under load and this problem is very tough to tackle unless we have the same component to directly and to replace.

Jestine

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Hi Foward,

Thank you for all news letters you send. I learn a new thing each time you send me.

You are welcome!

Iam sorry to bother you today with a Kingston TV which has a sound problem.

When I try to watch tv it does not bring out sound and if I try to connect it to a DVD player

still it does not produce sound. I checked the speeaker wires they are ok. But because Iam not

good on tracing faulty componets, would you assist me by by sending me Tv sound circuit diagram and

some tips to identify the faulty components.

Please help me.

May I thank you in advance for your help. May God bless you and your family as well as your business.

I suggest that you check on the audio ic and circuit and make sure there is supply to the audio ic. If the audio get the good supply voltage, you may need to replace the ic and retest. Sorry i do not keep any schematic diagram. You can visit http://www.eserviceinfo.com to check if there is a diagram for your tv model.

Jestine

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HI

Sorry it took so long to answer about the fault when I had the TV running

Felt one off the caps in the display panel so hot that I could not hold

My finger on it for long also on the display board 2 other cap slightly hot

Now when I switched it on the stand by light goes blue and now picture

And then cuts out, I did not have a chance to put the freezer on as I was called to go

To the hospital .

So when I get a chance I will take out the power supply and display

As it is one large board so do you think the caps the problem

 

This is the first time that I have felt a cap so hot is this a problem

Or have you seen the same when you have been repairing T.Vs

As I have never seen it all this years since I have been repairing

T.Vs

Eric

Hi Eric,

There are two reasons why a cap can turn hot. First is the cap itself is bad and the second one is the voltage across the cap is higher than the rated voltage of the cap. So you may need to check the voltage to make sure the voltage did not exceed the cap rated voltage.

Jestine

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I HAVE A PROBLEM WITH A SONY TV WHEN YOU POWER UP THE RELAY POWER DOWN I WANT TO KNOW  WHAT COULD BE PROBLEM THE POWER LIGHT KEEP ON OFF STILL TV DONT COME ON

HI Milton,

It could have some shorted components like HOT, FLYBACK, YOKE COIL and etc. Try isolate the problem using:

http://www.scribd.com/doc/2957819/TT204-Identifying-television-SMPS-problems

Jestine