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From: hr(bob) hofmann on 28 Dec 2009 15:58
On Dec 28, 5:22 am, "Mark Zacharias" <mark_zachar...(a)sbclobal.net>
wrote:
> "hr(bob) hofm...(a)att.net" <hrhofm...(a)att.net> wrote in message
>
> news:af21303e-1cc2-4fe4-b139-966e7c33b0bf(a)h9g2000yqa.googlegroups.com...
>
> > Just had a Sony Model KV-1380R given to me a couple of days ago.  Only
> > problem is simultaneous but intermittent horizontal and vertical
> > shrinkage of about 20%, on a random basis.  Removed the set back,
> > problem is still intermittent, but appears to be less frequent.  Tried
> > beating on anything related to power supply, both in normal and
> > trouble modes, no effects.  I suspect something in the power supply
> > since both H & V are affected.  Currently running the set with a
> > voltmeter on B+ which is running about 155V, waiting for something to
> > go wrong.  But I can't sit around watching the set, just check it
> > intermittently.  Anyone had similar problems with this or similar
> > Sonys. Photofact folder is 2564, putting manufacture date at sometime
> > in 1987 or early 1988.  If anyone has a pdf of this folder, please let
> > me know.
>
> Check for a bad 33uF 160 volt capacitor in the power supply.
>
> Mark Z.

So far I'm monitoring the output of the rectifiers on the AC power
line. If that voltage stays ok when there is a failure, I'll go to
the output of whatever regulator there is and start looking there.
The problem today is no failure at all. Hate intermittents!!!!
From: Sylvia Else on 28 Dec 2009 17:52
hr(bob) hofmann(a)att.net wrote:
> On Dec 28, 3:13 am, Sylvia Else <syl...(a)not.at.this.address> wrote:
>> hr(bob) hofm...(a)att.net wrote:
>>> Just had a Sony Model KV-1380R given to me a couple of days ago. Only
>>> problem is simultaneous but intermittent horizontal and vertical
>>> shrinkage of about 20%, on a random basis. Removed the set back,
>>> problem is still intermittent, but appears to be less frequent. Tried
>>> beating on anything related to power supply, both in normal and
>>> trouble modes, no effects. I suspect something in the power supply
>>> since both H & V are affected. Currently running the set with a
>>> voltmeter on B+ which is running about 155V, waiting for something to
>>> go wrong. But I can't sit around watching the set, just check it
>>> intermittently. Anyone had similar problems with this or similar
>>> Sonys. Photofact folder is 2564, putting manufacture date at sometime
>>> in 1987 or early 1988. If anyone has a pdf of this folder, please let
>>> me know.
>> Does the picture brightness remain the same?
>>
>> Sylvia.
>
> Yes, the brightness does not change. So far today the picture has
> been ok every time I looked at it.

Yet wouldn't one expect the brightness to increase noticeably if the
size decreases by 20%?

Sylvia.


From: Franc Zabkar on 28 Dec 2009 20:03
On Sun, 27 Dec 2009 21:54:47 -0800 (PST), "hr(bob) hofmann(a)att.net"
<hrhofmann(a)att.net> put finger to keyboard and composed:

>Just had a Sony Model KV-1380R given to me a couple of days ago. Only
>problem is simultaneous but intermittent horizontal and vertical
>shrinkage of about 20%, on a random basis.

It sounds like the EHT is increasing substantially. Does the set have
separate horizontal deflection and EHT generation circuits? Is there a
H-stat?

http://www.repairfaq.org/samnew/tvfaq/tvsonyhstat.htm

http://www.repairfaq.org/samnew/tvfaq/tvmohstat.htm

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.
From: Sylvia Else on 28 Dec 2009 21:36
Franc Zabkar wrote:
> On Sun, 27 Dec 2009 21:54:47 -0800 (PST), "hr(bob) hofmann(a)att.net"
> <hrhofmann(a)att.net> put finger to keyboard and composed:
>
>> Just had a Sony Model KV-1380R given to me a couple of days ago. Only
>> problem is simultaneous but intermittent horizontal and vertical
>> shrinkage of about 20%, on a random basis.
>
> It sounds like the EHT is increasing substantially. Does the set have
> separate horizontal deflection and EHT generation circuits? Is there a
> H-stat?
>
> http://www.repairfaq.org/samnew/tvfaq/tvsonyhstat.htm
>
> http://www.repairfaq.org/samnew/tvfaq/tvmohstat.htm
>
> - Franc Zabkar

Would also make the image brighter, wouldn't it?

Sylvia.
From: hr(bob) hofmann on 28 Dec 2009 22:55
On Dec 28, 8:36 pm, Sylvia Else <syl...(a)not.at.this.address> wrote:
> Franc Zabkar wrote:
> > On Sun, 27 Dec 2009 21:54:47 -0800 (PST), "hr(bob) hofm...(a)att.net"
> > <hrhofm...(a)att.net> put finger to keyboard and composed:
>
> >> Just had a Sony Model KV-1380R given to me a couple of days ago.  Only
> >> problem is simultaneous but intermittent horizontal and vertical
> >> shrinkage of about 20%, on a random basis.
>
> > It sounds like the EHT is increasing substantially. Does the set have
> > separate horizontal deflection and EHT generation circuits? Is there a
> > H-stat?
>
> >http://www.repairfaq.org/samnew/tvfaq/tvsonyhstat.htm
>
> >http://www.repairfaq.org/samnew/tvfaq/tvmohstat.htm
>
> > - Franc Zabkar
>
> Would also make the image brighter, wouldn't it?
>
> Sylvia.- Hide quoted text -
>
> - Show quoted text -

Sylvia:

It might, it is hard to tell if the image gets brighter since I have
never actually seen it make the transition from normal to shrunk.

Franc:

I will put my HV probe on the CRT HV cap and see if it varies. It
must be going up quite a lot to make that much difference in the
picture size. From my old TV days over the past 54 years, it is
almost always the reverse, the HV goes lower, and the picture gets
dimmer and noticeable bigger (blooming we call it on the west side of
the pond).
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