Help needed repairing SONY Trinitron TV

[arri]

Hi everybody,

I've got a broken KV-28WF1E Trinitron Sony TV set. The problem is
regarded with the power suply unit. I've changed the main power IC
regulator because it failed. Now the TV set powers on but inmediately
shutdowns again. Has anybody schematics of this TV PSU?

TIA,
Arri

 

[Sofie]

arri:
The problem may not be in the PS but rather the circuitry it feeds. Be
certain that there is no faulty circuitry that is presenting too much of a
load on the PSU thus causing it to shut down. The first place I would look
is around the HOT and the flyback and the flyback derived B+ circuitry.

 

[mo]

arri:
The problem may not be in the PS but rather the circuitry it feeds. Be
certain that there is no faulty circuitry that is presenting too much of a
load on the PSU thus causing it to shut down. The first place I would look
is around the HOT and the flyback and the flyback derived B+ circuitry.
--
Best Regards,
Daniel Sofie
Electronics Supply & Repair
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Still doesn't answer his question.

 

[Sofie]

mo:

He may not need the power supply schematic if he first troubleshoots the
other circuitry and discovers shorted components that are causing the supply
to shut down.

And, by the way, what's it to you?
Are the new newsgroup monitor or what?
And furthermore, how have you contributed in a positive way to this thread?

Dan
----------------------------

 

[mo]

And, by the way, what's it to you?
Are the new newsgroup monitor or what?
And furthermore, how have you contributed in a positive way to this thread?

Dan
----------------------------

He had a go.Now he got to the stage where he needed a circuit diagram.
So that's what his question was.
Can anyone provide me with a circuit diagram.The bloke didn't want
your analysis.

I attempted to alert you to the question,but you still can't see it.

How would you like it if you went to a cafe bar and asked for a coffee
and the waiter delivered you a cup of tea instead.

Nothing personal,just trying to correct a common error.

 

[b]

If we're talking about "correcting common errors" here, I believe what
Dan suggested is exactly that - correcting the misconception that to
solve ANY problem all you need is to instantly reach for the
schematic. He was trying to save the OP time if you ask me. And I'm
equally sure the OP does not need you to say what is or isn't useful
information for him.
Ben

[email protected] (mo) wrote in messages snip)> He had a go.Now he got to the stage where he needed a circuit diagram.

 

[Stefan Toftevall]

Hi everybody,

I've got a broken KV-28WF1E Trinitron Sony TV set. The problem is
regarded with the power suply unit. I've changed the main power IC
regulator because it failed. Now the TV set powers on but inmediately
shutdowns again. Has anybody schematics of this TV PSU?

TIA,
Arri

Hello Arri,
Be sure to replace the small electrolytes on the primary side of the
PSU, around the IC you replaced and such.

Here's a test you can do to see if the PSU is operating and regulates
correctly.
Take the Horizontal output transistor away from the board.
Connect a 60W lampbulb across the B+ supply filter electrolyte, that
is secondary side of the power supply. This will simulate the load of
the horizontal circuit. Hook up a voltmeter across the bulb.
If the PSU is ok, the bulb will light continously and you'll have
around 150VDC across it.
If the bulb lights up, then goes off, your problem is probably on the
primary side. Of course, things like shorted secondary rectifier
diodes on low-voltage supplies could place an excessive burden on the
PSU, and shuts down due to overloading. But that's more rare.

Hope this helps,

Regards
Stefan

 

[David]

I am sure you can buy the service manual from Sony. Won't be cheap
though.
Once you have the service manual, you can start tracking down all the
different shutdown circuits involved.

David

 

[mo]

[email protected] (b) wrote in message
He was trying to save the OP time if you ask me. And I'm

equally sure the OP does not need you to say what is or isn't useful
information for him.
Ben

What's an "OP" there padre?
Maybe you could say a prayer for our poor brother whose tv is on the
brink of departing to a better place.

 

[sofie]

OP = Original Post (er)
NG = NewsGroup
AH = mo

 

[arri]

Hi,

Thank you everybody for the information regarding how to solve the
problem. I'm not an expert at all in TV problems so that all
information is welcome for me.
Arri

 

[mo]

OP = Original Post (er)
NG = NewsGroup
AH = mo
----------------------------------

Too much information.
One thing leads to another.
Now I'm lost with the " AH = mo "
Anyway,thanks for the O/P on my I/P about the OP.

Cheers - Mo