Problem with vertical sweep on Toshiba CF2665K TV Set

S

Stephan Greppi

Guest
I have aToshiba CF2665K that is experiencing vertical sweep problem (about
half the vertical picture with retrace lines).
This has been worsening slowly, and I'm pretty sure it's a defective
capacitor somewhere in the vertical circuitry.
The problem is I cannot find the schematic anymore.
Would anybody have a schematic for this TV, so I can locate the capacitors ?
Thanks
Stephan
 
Replace all the capacitors with the same first number as the vertical output
ic. i.e. vertical output ic IC301, replace C301,C305,C308 and maybe a
couple more.


"Stephan Greppi" <sgreppi@hotmail.com> wrote in message
news:GIlic.14904$_L6.1153842@attbi_s53...
I have aToshiba CF2665K that is experiencing vertical sweep problem
(about
half the vertical picture with retrace lines).
This has been worsening slowly, and I'm pretty sure it's a defective
capacitor somewhere in the vertical circuitry.
The problem is I cannot find the schematic anymore.
Would anybody have a schematic for this TV, so I can locate the capacitors
?
Thanks
Stephan
Click to expand...
 
I am guessing you mean your top half of the pix is stretching, starting
to foldover or something like that...(usually what folks call "retrace
lines" will cover the entire screen)
lots of folks just use the shotgun method—replace all the electroytics
in the vert vertretrn circuit. Caps are cheap, & you may save yourself
another repair down the road perhaps.
Or you can get the pinout of your vert ic for a bit of guidance.
Reflow any poor looking solder in the area (and any poor
solder-high-heat areas while you are at it)
Once again, you may save yourself another repair in the future
 
Hi,
I replaced all electrolytic capacitors Cxxx I could find. I don't have a
schematic, but I guess C3xx are capacitors in the vertical deflection
circuitry.
I also changed IC301, R287 and a couple diodes.
The result is still the same. It started by the top of the picture starting
to elongate, and then the picture progresively diminushing in size over a
few weeks. It is now about half the size of a normal picture, in the middle
of the screen, with retrace lines visible when no RF signal is present.
What else should I try before I trash the TV?
Suggestions anyone?
Thaks in advance.
Stephan



"David" <dkuhajda@locl.net.spam> wrote in message
news:408ad59d$1@news.greennet.net...
Replace all the capacitors with the same first number as the vertical
output
ic. i.e. vertical output ic IC301, replace C301,C305,C308 and maybe a
couple more.


"Stephan Greppi" <sgreppi@hotmail.com> wrote in message
news:GIlic.14904$_L6.1153842@attbi_s53...
I have aToshiba CF2665K that is experiencing vertical sweep problem
(about
half the vertical picture with retrace lines).
This has been worsening slowly, and I'm pretty sure it's a defective
capacitor somewhere in the vertical circuitry.
The problem is I cannot find the schematic anymore.
Would anybody have a schematic for this TV, so I can locate the
capacitors
?
Thanks
Stephan
Click to expand...
 
Stephan Greppi wrote:

Hi,
I replaced all electrolytic capacitors Cxxx I could find. I don't have a
schematic, but I guess C3xx are capacitors in the vertical deflection
circuitry.
I also changed IC301, R287 and a couple diodes.
The result is still the same. It started by the top of the picture starting
to elongate, and then the picture progresively diminushing in size over a
few weeks. It is now about half the size of a normal picture, in the middle
of the screen, with retrace lines visible when no RF signal is present.
What else should I try before I trash the TV?
Suggestions anyone?
Thaks in advance.
Stephan
Click to expand...
Hi...

Don't trash it for that; specially not since you've
already invested in it.

Betcha a donut that there's one cap left you haven't
yet found. Not necessarily near the ones you did find.
Probably larger, higher voltage. Keep looking.

I like chocolate covered :)

Take care.

Ken
 
Be advised one of the caps in teh vertical ckt is physically located near
the jungel ic. It also may contribrute to your symptom.
"Ken Weitzel" <kweitzel@shaw.ca> wrote in message
news:8uDnc.407211$Pk3.375340@pd7tw1no...
Stephan Greppi wrote:

Hi,
I replaced all electrolytic capacitors Cxxx I could find. I don't have a
schematic, but I guess C3xx are capacitors in the vertical deflection
circuitry.
I also changed IC301, R287 and a couple diodes.
The result is still the same. It started by the top of the picture
starting
to elongate, and then the picture progresively diminushing in size over a
few weeks. It is now about half the size of a normal picture, in the
middle
of the screen, with retrace lines visible when no RF signal is present.
What else should I try before I trash the TV?
Suggestions anyone?
Thaks in advance.
Stephan

Hi...

Don't trash it for that; specially not since you've
already invested in it.

Betcha a donut that there's one cap left you haven't
yet found. Not necessarily near the ones you did find.
Probably larger, higher voltage. Keep looking.

I like chocolate covered :)

Take care.

Ken
Click to expand...
 
I finally figured out what the problem was.
I had purchased a repair kit from Tritronics fot that TV, and the
instructions said to replace C301 and C305 with 2.2 MF (instead of the
original 1.0MF), which I faithfully did.
Turns out these 2 caps were indeed leaking, but they should be replaced by
1.0 MF and not 2.2MF.
Anyway it's fixed now, and even though I changed 8 caps, a few diodes and
the IC301 for nothing, it still was well worth it.
Thanks for the help.
Stephan



"Stephan Greppi" <sgreppi@hotmail.com> wrote in message
news:%kCnc.16725$xw3.1130314@attbi_s04...
Hi,
I replaced all electrolytic capacitors Cxxx I could find. I don't have a
schematic, but I guess C3xx are capacitors in the vertical deflection
circuitry.
I also changed IC301, R287 and a couple diodes.
The result is still the same. It started by the top of the picture
starting
to elongate, and then the picture progresively diminushing in size over a
few weeks. It is now about half the size of a normal picture, in the
middle
of the screen, with retrace lines visible when no RF signal is present.
What else should I try before I trash the TV?
Suggestions anyone?
Thaks in advance.
Stephan



"David" <dkuhajda@locl.net.spam> wrote in message
news:408ad59d$1@news.greennet.net...
Replace all the capacitors with the same first number as the vertical
output
ic. i.e. vertical output ic IC301, replace C301,C305,C308 and maybe a
couple more.


"Stephan Greppi" <sgreppi@hotmail.com> wrote in message
news:GIlic.14904$_L6.1153842@attbi_s53...
I have aToshiba CF2665K that is experiencing vertical sweep problem
(about
half the vertical picture with retrace lines).
This has been worsening slowly, and I'm pretty sure it's a defective
capacitor somewhere in the vertical circuitry.
The problem is I cannot find the schematic anymore.
Would anybody have a schematic for this TV, so I can locate the
capacitors
?
Thanks
Stephan
Click to expand...
 
Hey, congratulations!

But the coffee's ready, and the donuts haven't
arrived :)

Take care.

Ken


Stephan Greppi wrote:
I finally figured out what the problem was.
I had purchased a repair kit from Tritronics fot that TV, and the
instructions said to replace C301 and C305 with 2.2 MF (instead of the
original 1.0MF), which I faithfully did.
Turns out these 2 caps were indeed leaking, but they should be replaced by
1.0 MF and not 2.2MF.
Anyway it's fixed now, and even though I changed 8 caps, a few diodes and
the IC301 for nothing, it still was well worth it.
Thanks for the help.
Stephan



"Stephan Greppi" <sgreppi@hotmail.com> wrote in message
news:%kCnc.16725$xw3.1130314@attbi_s04...

Hi,
I replaced all electrolytic capacitors Cxxx I could find. I don't have a
schematic, but I guess C3xx are capacitors in the vertical deflection
circuitry.
I also changed IC301, R287 and a couple diodes.
The result is still the same. It started by the top of the picture

starting

to elongate, and then the picture progresively diminushing in size over a
few weeks. It is now about half the size of a normal picture, in the

middle

of the screen, with retrace lines visible when no RF signal is present.
What else should I try before I trash the TV?
Suggestions anyone?
Thaks in advance.
Stephan



"David" <dkuhajda@locl.net.spam> wrote in message
news:408ad59d$1@news.greennet.net...

Replace all the capacitors with the same first number as the vertical

output

ic. i.e. vertical output ic IC301, replace C301,C305,C308 and maybe a
couple more.


"Stephan Greppi" <sgreppi@hotmail.com> wrote in message
news:GIlic.14904$_L6.1153842@attbi_s53...

I have aToshiba CF2665K that is experiencing vertical sweep problem

(about

half the vertical picture with retrace lines).
This has been worsening slowly, and I'm pretty sure it's a defective
capacitor somewhere in the vertical circuitry.
The problem is I cannot find the schematic anymore.
Would anybody have a schematic for this TV, so I can locate the

capacitors

?

Thanks
Stephan
Click to expand...
 
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