Toshiba Model # CF2765K Chassis #: 9010 Vertical Problem

R

Robert McPherson

Guest
Set originally had bad linearity at top & side bowing (pincusion)
problems.
I have fixed both of those problems, but still have about 1" of black
space at bottom of raster. There is no available Howard Sams
Photofact on this model or chassis that was produced. I have changed
all of the usual capacitors, and replaced the AN5521 vertical IC. All
of the waveforms going into and out of the IC appear normal. All of
the DC voltages on the 7 pins of the IC are normal, EXCEPT possibly
for pin 2 (Vertical output) The DC voltage is almost 8 volts, but the
DC voltage called for on a similar? Toshiba TV (Model # CF2665K)for
which I do have a Photofact calls for 15 volts on Pin 2. The diagram
I have seems to be very closely related, but it does not show a
pincusion board which my set has. I am wondering if the DC voltage on
pin2 of my customers TV should also be 15 volts, and if so, why is it
lower About 8 volts) than normal. I can not tell from my diagram
where the DC voltage on pin 2 should be coming from. Any ideas?
Anyone have a scanned section of the exact schematic which you are
willing to Email me as an attachment? Thanks for your help. Robert
McPherson. rm502@bellsouth.net
 
You missed one cap....Near the jungle IC.
kip


--
"Watch the return E-Mail addy its false"
"Robert McPherson" <rm502@bellsouth.net> wrote in message
news:1fe013f5.0309241147.742341c4@posting.google.com...
Set originally had bad linearity at top & side bowing (pincusion)
problems.
I have fixed both of those problems, but still have about 1" of black
space at bottom of raster. There is no available Howard Sams
Photofact on this model or chassis that was produced. I have changed
all of the usual capacitors, and replaced the AN5521 vertical IC. All
of the waveforms going into and out of the IC appear normal. All of
the DC voltages on the 7 pins of the IC are normal, EXCEPT possibly
for pin 2 (Vertical output) The DC voltage is almost 8 volts, but the
DC voltage called for on a similar? Toshiba TV (Model # CF2665K)for
which I do have a Photofact calls for 15 volts on Pin 2. The diagram
I have seems to be very closely related, but it does not show a
pincusion board which my set has. I am wondering if the DC voltage on
pin2 of my customers TV should also be 15 volts, and if so, why is it
lower About 8 volts) than normal. I can not tell from my diagram
where the DC voltage on pin 2 should be coming from. Any ideas?
Anyone have a scanned section of the exact schematic which you are
willing to Email me as an attachment? Thanks for your help. Robert
McPherson. rm502@bellsouth.net
Click to expand...
 
Check that diode close to the heat sink for leakage.

kip

--
"Watch the return E-Mail addy its false"
"Robert McPherson" <rm502@bellsouth.net> wrote in message
news:1fe013f5.0309241147.742341c4@posting.google.com...
Set originally had bad linearity at top & side bowing (pincusion)
problems.
I have fixed both of those problems, but still have about 1" of black
space at bottom of raster. There is no available Howard Sams
Photofact on this model or chassis that was produced. I have changed
all of the usual capacitors, and replaced the AN5521 vertical IC. All
of the waveforms going into and out of the IC appear normal. All of
the DC voltages on the 7 pins of the IC are normal, EXCEPT possibly
for pin 2 (Vertical output) The DC voltage is almost 8 volts, but the
DC voltage called for on a similar? Toshiba TV (Model # CF2665K)for
which I do have a Photofact calls for 15 volts on Pin 2. The diagram
I have seems to be very closely related, but it does not show a
pincusion board which my set has. I am wondering if the DC voltage on
pin2 of my customers TV should also be 15 volts, and if so, why is it
lower About 8 volts) than normal. I can not tell from my diagram
where the DC voltage on pin 2 should be coming from. Any ideas?
Anyone have a scanned section of the exact schematic which you are
willing to Email me as an attachment? Thanks for your help. Robert
McPherson. rm502@bellsouth.net
Click to expand...
 
Make sure you changed these caps....

C301 And C305 Both 1 Uf @ 50v 105 Degree C. and C308 220uf 35v

If problem still exists , check the fusible resistor value that feeds B+ to
the IC...if it increases it will cause the circuit to choke.


--
==========================
Jeff Stielau
Shoreline Electronics Repair
344 East Main Street
Clinton,CT 06413
860-399-1861
860-664-3535 (fax)
jstielau@snet.net
==========================
"If you push something hard enough it will fall over."
Fudd's First Law of Opposition - Sir Sidney Fudd


"Robert McPherson" <rm502@bellsouth.net> wrote in message
news:1fe013f5.0309241147.742341c4@posting.google.com...
Set originally had bad linearity at top & side bowing (pincusion)
problems.
I have fixed both of those problems, but still have about 1" of black
space at bottom of raster. There is no available Howard Sams
Photofact on this model or chassis that was produced. I have changed
all of the usual capacitors, and replaced the AN5521 vertical IC. All
of the waveforms going into and out of the IC appear normal. All of
the DC voltages on the 7 pins of the IC are normal, EXCEPT possibly
for pin 2 (Vertical output) The DC voltage is almost 8 volts, but the
DC voltage called for on a similar? Toshiba TV (Model # CF2665K)for
which I do have a Photofact calls for 15 volts on Pin 2. The diagram
I have seems to be very closely related, but it does not show a
pincusion board which my set has. I am wondering if the DC voltage on
pin2 of my customers TV should also be 15 volts, and if so, why is it
lower About 8 volts) than normal. I can not tell from my diagram
where the DC voltage on pin 2 should be coming from. Any ideas?
Anyone have a scanned section of the exact schematic which you are
willing to Email me as an attachment? Thanks for your help. Robert
McPherson. rm502@bellsouth.net
Click to expand...
 
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