This is an oldie, the model slips my mind, but its a CTC167R chassis, thats
a vertical wood floor model.

This set has worked flawlessly since the date it was purchased new at
stienburgs(now defunct).

about a month ago, the vertical began to foldover at the top.

When you first would turn the set on, the foldover would appear. as it ran
for an hour it would retract and clear up. I knew right there, it has to be
a faulty cap in the vert stages.

over the course of the 2 months, it got worse and worse, to the point where
when you first turned it on, the foldover would reach as far down as the
center of the screen. after an hour, it would retract to about a 1/4 of the
screen, but it never disappeard.

Just today, the set was turned off, and then later in the day, turned back
on, BAM no vertical deflection. none. zippo. The OSD is there, the sound is
there, but no pic, no vert.

just a line with OSD.

Im believing that the cap has either shorted, or opened up.

I did some research in the faq, and euras and found that supply diodes open,
or a resistor changes in value. I also found a pinout of the IC, and low
voltages would indicate faulty IC, or faulty coupleing cap.

I checked out the vcc volts to the IC, they are dead on. The IC isnt the
problem.

I checked the resistor, and the diodes it suggested in the euras database,
and they are fine. the supplies are good.

Any ideas if this is a common problem? or maybe this has happened before,
and know what cap it is? I dont have an ESR meter, but I have a DMM and a
scope.

This is commonly from bad electro caps in the vertical deflection section.
You should use an ESR meter to test them, or change them to test. There may
be more than a few that are too high in ESR. If any of the caps went too far
out, there is a chance that other damage has also occurred. This is why when
there are faults starting, it is wise to service the set right away.

--

Greetings,

Jerry Greenberg GLG Technologies GLG
=========================================
WebPage http://www.zoom-one.com
Electronics http://www.zoom-one.com/electron.htm
=========================================


"Mike" wrote in message
...
This is an oldie, the model slips my mind, but its a CTC167R chassis, thats
a vertical wood floor model.

This set has worked flawlessly since the date it was purchased new at
stienburgs(now defunct).

about a month ago, the vertical began to foldover at the top.

When you first would turn the set on, the foldover would appear. as it ran
for an hour it would retract and clear up. I knew right there, it has to be
a faulty cap in the vert stages.

over the course of the 2 months, it got worse and worse, to the point where
when you first turned it on, the foldover would reach as far down as the
center of the screen. after an hour, it would retract to about a 1/4 of the
screen, but it never disappeard.

Just today, the set was turned off, and then later in the day, turned back
on, BAM no vertical deflection. none. zippo. The OSD is there, the sound is
there, but no pic, no vert.

just a line with OSD.

Im believing that the cap has either shorted, or opened up.

I did some research in the faq, and euras and found that supply diodes open,
or a resistor changes in value. I also found a pinout of the IC, and low
voltages would indicate faulty IC, or faulty coupleing cap.

I checked out the vcc volts to the IC, they are dead on. The IC isnt the
problem.

I checked the resistor, and the diodes it suggested in the euras database,
and they are fine. the supplies are good.

Any ideas if this is a common problem? or maybe this has happened before,
and know what cap it is? I dont have an ESR meter, but I have a DMM and a
scope.

i know its a capacitor(s).

im wondering which ones.





"Jerry G." wrote in message
...
This is commonly from bad electro caps in the vertical deflection section.
You should use an ESR meter to test them, or change them to test. There
may
be more than a few that are too high in ESR. If any of the caps went too
far
out, there is a chance that other damage has also occurred. This is why
when
there are faults starting, it is wise to service the set right away.

--

Greetings,

Jerry Greenberg GLG Technologies GLG
=========================================
WebPage http://www.zoom-one.com
Electronics http://www.zoom-one.com/electron.htm
=========================================


"Mike" wrote in message
...
This is an oldie, the model slips my mind, but its a CTC167R chassis,
thats
a vertical wood floor model.

This set has worked flawlessly since the date it was purchased new at
stienburgs(now defunct).

about a month ago, the vertical began to foldover at the top.

When you first would turn the set on, the foldover would appear. as it ran
for an hour it would retract and clear up. I knew right there, it has to
be
a faulty cap in the vert stages.

over the course of the 2 months, it got worse and worse, to the point
where
when you first turned it on, the foldover would reach as far down as the
center of the screen. after an hour, it would retract to about a 1/4 of
the
screen, but it never disappeard.

Just today, the set was turned off, and then later in the day, turned back
on, BAM no vertical deflection. none. zippo. The OSD is there, the sound
is
there, but no pic, no vert.

just a line with OSD.

Im believing that the cap has either shorted, or opened up.

I did some research in the faq, and euras and found that supply diodes
open,
or a resistor changes in value. I also found a pinout of the IC, and low
voltages would indicate faulty IC, or faulty coupleing cap.

I checked out the vcc volts to the IC, they are dead on. The IC isnt the
problem.

I checked the resistor, and the diodes it suggested in the euras database,
and they are fine. the supplies are good.

Any ideas if this is a common problem? or maybe this has happened before,
and know what cap it is? I dont have an ESR meter, but I have a DMM and a
scope.

The capacitors that need replaced are the ones that will test bad in the
vertical circuit with an ESR meter. The IC is probably toast if you now
have zero vertical deflection.
David

"Mike" wrote in message
...
i know its a capacitor(s).

im wondering which ones.





"Jerry G." wrote in message
...
This is commonly from bad electro caps in the vertical deflection
section.
You should use an ESR meter to test them, or change them to test. There
may
be more than a few that are too high in ESR. If any of the caps went too
far
out, there is a chance that other damage has also occurred. This is why
when
there are faults starting, it is wise to service the set right away.

--

Greetings,

Jerry Greenberg GLG Technologies GLG
=========================================
WebPage http://www.zoom-one.com
Electronics http://www.zoom-one.com/electron.htm
=========================================


"Mike" wrote in message
...
This is an oldie, the model slips my mind, but its a CTC167R chassis,
thats
a vertical wood floor model.

This set has worked flawlessly since the date it was purchased new at
stienburgs(now defunct).

about a month ago, the vertical began to foldover at the top.

When you first would turn the set on, the foldover would appear. as it
ran
for an hour it would retract and clear up. I knew right there, it has to
be
a faulty cap in the vert stages.

over the course of the 2 months, it got worse and worse, to the point
where
when you first turned it on, the foldover would reach as far down as the
center of the screen. after an hour, it would retract to about a 1/4 of
the
screen, but it never disappeard.

Just today, the set was turned off, and then later in the day, turned
back
on, BAM no vertical deflection. none. zippo. The OSD is there, the sound
is
there, but no pic, no vert.

just a line with OSD.

Im believing that the cap has either shorted, or opened up.

I did some research in the faq, and euras and found that supply diodes
open,
or a resistor changes in value. I also found a pinout of the IC, and low
voltages would indicate faulty IC, or faulty coupleing cap.

I checked out the vcc volts to the IC, they are dead on. The IC isnt the
problem.

I checked the resistor, and the diodes it suggested in the euras
database,
and they are fine. the supplies are good.

Any ideas if this is a common problem? or maybe this has happened
before,
and know what cap it is? I dont have an ESR meter, but I have a DMM and
a
scope.

"Mike" wrote in message
...
i know its a capacitor(s).

im wondering which ones.



The bad ones, what else can people tell you without looking at the set?
Obviously they'll be near the vertical output chip, unless you have an ESR
meter you'll just have to replace all the ones in the area. As someone else
said, you most likely fried the IC by continuing to use the set, so this
should be replaced as well.

Subject: RCA Proscan 27" TV no vertical
From: "David"
Date: 2/10/04 5:38 PM Pacific Standard Time
Message-id:

The IC is probably toast if you now
have zero vertical deflection.
David


Can't be, he said he checked it:

"I checked out the vcc volts to the IC, they are dead on. The IC isnt the
problem."

John

"John Del" wrote in message
...
Subject: RCA Proscan 27" TV no vertical
From: "David"
Date: 2/10/04 5:38 PM Pacific Standard Time
Message-id:

The IC is probably toast if you now
have zero vertical deflection.
David


Can't be, he said he checked it:

"I checked out the vcc volts to the IC, they are dead on. The IC isnt the
problem."

John

He checked Vcc at the IC and it's ok, that doesn't mean the IC is. That's
like checking for voltage at the wall outlet and assuming the TV is ok.

of all the TVs i have seen, when the IC goes, it takes out the B+ supply. so
you tell me.



"James Sweet" wrote in message
news:P6AWb.9804$jk2.27669@attbi_s53...

"John Del" wrote in message
...
Subject: RCA Proscan 27" TV no vertical
From: "David"
Date: 2/10/04 5:38 PM Pacific Standard Time
Message-id:

The IC is probably toast if you now
have zero vertical deflection.
David


Can't be, he said he checked it:

"I checked out the vcc volts to the IC, they are dead on. The IC isnt
the
problem."

John

He checked Vcc at the IC and it's ok, that doesn't mean the IC is. That's
like checking for voltage at the wall outlet and assuming the TV is ok.

"Mike" wrote in message
...
of all the TVs i have seen, when the IC goes, it takes out the B+ supply.
so
you tell me.



Most do that, I have however come across failed IC's without shorting,
either way the capacitors need replacing.

On Thu, 12 Feb 2004 02:04:25 GMT, "James Sweet"
wrote:


"Mike" wrote in message
...
of all the TVs i have seen, when the IC goes, it takes out the B+ supply.
so
you tell me.



Most do that, I have however come across failed IC's without shorting,
either way the capacitors need replacing.

Ditto here, not just RCA. I see that like this in other brands like
JVC (frequently cooks cap then vertical IC dies because of too small
heatsink, either steel Baaaaad!, or aluminum), Panasonic, Samsung etc.
Sometimes takes out vertical supply diode (from flyback transformer).

If it is my TV and being tv tech, I'd oversize the vertical heatsink.
To others, do you do this?

I wondered what IC maker designed this LA7832, LA7838 etc package
style doesn't look good for heavy duty heat transfer, so tiny die pad
and thin also and off center from mounting hole. Looks like this
requires special clamp to squeeze the die pad & heatsink evenly.
(thick bars & pair of bolts & nuts will do nicely).

I like the type used TO-220 (TDA8172), AN5521 (two hole w/ thick tab)
etc. TDA8350Q but lousy vertical design.

Or use a switching techinque applied to vertical sweep would be
better. RCA did similar idea with CTC168/CTC169. But I would like to
see this brought up to date and needs no heatsink or small one.

Cheers,

Wizard

Mike.....
No so..... many times when the Vertical Output chip fails or shorts out,
the excessive current draw will open up a low ohm resistor or the diode
coming from one of the flyback windings..... or the chip will fail
internally and not cause excessive current draw...... no matter.....no
vertical deflection, just a narrow line across the screen and the main B+ is
still running just fine. Usually the chip will fail because of
deteriorating electrolytics in the surrounding circuitry and possibly
because of dry or cracked solder joints where the chip is soldered to the
board..... that is why it is important to get the set repair when it first
shows any symptoms and is still limping along........ otherwise the chip is
toast.
--
Best Regards,
Daniel Sofie
Electronics Supply & Repair
----------------------------------


"Mike" wrote in message
...
of all the TVs i have seen, when the IC goes, it takes out the B+ supply.
so
you tell me.



"James Sweet" wrote in message
news:P6AWb.9804$jk2.27669@attbi_s53...

"John Del" wrote in message
...
Subject: RCA Proscan 27" TV no vertical
From: "David"
Date: 2/10/04 5:38 PM Pacific Standard Time
Message-id:

The IC is probably toast if you now
have zero vertical deflection.
David


Can't be, he said he checked it:

"I checked out the vcc volts to the IC, they are dead on. The IC isnt
the
problem."

John

He checked Vcc at the IC and it's ok, that doesn't mean the IC is.
That's
like checking for voltage at the wall outlet and assuming the TV is ok.

No you are wrong.....Panasonic LA7836,s go and dont take out nothing.
Just bad caps along with bad IC.

kip

--
"Watch the return E-Mail addy its false"
"Mike" wrote in message
...
of all the TVs i have seen, when the IC goes, it takes out the B+ supply.
so
you tell me.



"James Sweet" wrote in message
news:P6AWb.9804$jk2.27669@attbi_s53...

"John Del" wrote in message
...
Subject: RCA Proscan 27" TV no vertical
From: "David"
Date: 2/10/04 5:38 PM Pacific Standard Time
Message-id:

The IC is probably toast if you now
have zero vertical deflection.
David


Can't be, he said he checked it:

"I checked out the vcc volts to the IC, they are dead on. The IC isnt
the
problem."

John

He checked Vcc at the IC and it's ok, that doesn't mean the IC is.
That's
like checking for voltage at the wall outlet and assuming the TV is ok.