Hello,

I have a Sony KV J 29MN1AK about 5 years old.

This TV has developed problems. It shows green colour lines slanted
towards right and spread across the entire screen. I have not
counted them, but these lines are mostly equally separated ( may be
about 1.5cms apart)

This seems to me a vertical flyback problem where the beams are not
blanked.

Can some experts in this forum help me to fix this problem ?

On Nov 24, 1:34 am, MP wrote:
Hello,

I have a Sony KV J 29MN1AK about 5 years old.

This TV has developed problems. It shows green colour lines slanted
towards right and spread across the entire screen. I have not
counted them, but these lines are mostly equally separated ( may be
about 1.5cms apart)

This seems to me a vertical flyback problem where the beams are not
blanked.

Can some experts in this forum help me to fix this problem ?

Sorry, forgot to mention that the audio and video is perfectly fine.
These green lines appear on the picture and not very very bright but
visible and is irritating.

MP wrote:

Hello,

I have a Sony KV J 29MN1AK about 5 years old.

This TV has developed problems. It shows green colour lines slanted
towards right and spread across the entire screen. I have not
counted them, but these lines are mostly equally separated ( may be
about 1.5cms apart)

This seems to me a vertical flyback problem where the beams are not
blanked.

Can some experts in this forum help me to fix this problem ?

sounds like bad caps to me.



--
"I'm never wrong, once i thought i was, but was mistaken"
Real Programmers Do things like this.
http://webpages.charter.net/jamie_5

MP wrote:

On Nov 24, 1:34 am, MP wrote:

Hello,

I have a Sony KV J 29MN1AK about 5 years old.

This TV has developed problems. It shows green colour lines slanted
towards right and spread across the entire screen. I have not
counted them, but these lines are mostly equally separated ( may be
about 1.5cms apart)

This seems to me a vertical flyback problem where the beams are not
blanked.

Can some experts in this forum help me to fix this problem ?


Sorry, forgot to mention that the audio and video is perfectly fine.
These green lines appear on the picture and not very very bright but
visible and is irritating.
yes, they are very thin and slant slight downward correct?


--
"I'm never wrong, once i thought i was, but was mistaken"
Real Programmers Do things like this.
http://webpages.charter.net/jamie_5

On Nov 24, 1:41 am, Jamie
t wrote:
MP wrote:
On Nov 24, 1:34 am, MP wrote:

Hello,

I have a Sony KV J 29MN1AK about 5 years old.

This TV has developed problems. It shows green colour lines slanted
towards right and spread across the entire screen. I have not
counted them, but these lines are mostly equally separated ( may be
about 1.5cms apart)

This seems to me a vertical flyback problem where the beams are not
blanked.

Can some experts in this forum help me to fix this problem ?

Sorry, forgot to mention that the audio and video is perfectly fine.
These green lines appear on the picture and not very very bright but
visible and is irritating.

yes, they are very thin and slant slight downward correct?

--
"I'm never wrong, once i thought i was, but was mistaken"
Real Programmers Do things like this.http://webpages.charter.net/jamie_5- Hide quoted text -

- Show quoted text -

right... but how do i figure out the bad cap's ?
if it was a retrace path problem, i should be seeing white lines...
how do u explain the green lines ?

There are several things that can cause your fault. It may be a
failure in the blanking circuits, or the picture tube is going
defective. Take the TV for a service estimate. This is not something
you will be able to service yourself without the proper training,
tools, and service information. It will involve troubleshooting,
ordering parts, and possibly doing some adjustments. If the fault is
the tube, then the set will not be worth to service.

Jerry G.
=====


On Nov 23, 3:34 pm, MP wrote:
Hello,

I have a Sony KV J 29MN1AK about 5 years old.

This TV has developed problems. It shows green colour lines slanted
towards right and spread across the entire screen. I have not
counted them, but these lines are mostly equally separated ( may be
about 1.5cms apart)

This seems to me a vertical flyback problem where the beams are not
blanked.

Can some experts in this forum help me to fix this problem ?

"Jerry G." wrote in message
...
There are several things that can cause your fault. It may be a
failure in the blanking circuits, or the picture tube is going
defective. Take the TV for a service estimate. This is not something
you will be able to service yourself without the proper training,
tools, and service information. It will involve troubleshooting,
ordering parts, and possibly doing some adjustments. If the fault is
the tube, then the set will not be worth to service.




Do you ever contribute anything useful to the group? All I ever see are
canned responses telling people to take things in for service. Yes in many
cases that's the best solution, but much of the time the stuff is not worth
paying to have serviced and someone may as well take a shot at it. Don't be
so quick to assume people are incompetent even if most of them are.

On Nov 23, 2:34 pm, MP wrote:
Hello,

I have a Sony KV J 29MN1AK about 5 years old.

This TV has developed problems. It shows green colour lines slanted
towards right and spread across the entire screen. I have not
counted them, but these lines are mostly equally separated ( may be
about 1.5cms apart)

This seems to me a vertical flyback problem where the beams are not
blanked.

Can some experts in this forum help me to fix this problem ?

Do you have access to an oscilloscope and the schematic for the set??


H. R. (Bob) Hofmann

On Nov 24, 10:25 am, "hr(bob) "
wrote:
On Nov 23, 2:34 pm, MP wrote:

Hello,

I have a Sony KV J 29MN1AK about 5 years old.

This TV has developed problems. It shows green colour lines slanted
towards right and spread across the entire screen. I have not
counted them, but these lines are mostly equally separated ( may be
about 1.5cms apart)

This seems to me a vertical flyback problem where the beams are not
blanked.

Can some experts in this forum help me to fix this problem ?

Do you have access to an oscilloscope and the schematic for the set??

H. R. (Bob) Hofmann

James
Thanks for your suggestion. Of course going to the technician is
choice, but my approach towards this is a bit of learning, rekindle my
electronics enthusiasm and also have enough knowledge about the fault
so that the technician does not fool me by robbing a moolah and just
replace a resistor/capacitor. I am sure you would encourage people
learn things.

Hoffmann
I dont have access to the oscilloscope or schematic of the set. Is
there any way, I could download the service manual and schematc of
this set... do you guys know of some good free websites that provide
tips of Sony TV repair ?


All
I have a slight correction to the problem. I went very very close to
the TV and realised that the lines are not green but white color. I
dont know why they appeared green to me from distance... anyways. I
counted them. They are about 22 in total spread over the screen.
The distance between the bottom two is about my two fingers and
gradually the distance between lines starts to decrease with the
topmost having lesser than my index finger. They are slanted upwards
towards right , yes upwards !! and NOT downwards. The bottom most
line kind of starts from the centre of the screen. Most of the lines
are the centre of the screen do not touch the leftmost and right most
edges giving the whole pattern kind of a fat hour glass look.

Now since these are white colour , i suspect these may be got to do
with the vertical flyback blanking system.

"hr(bob) " wrote in message
...
On Nov 23, 2:34 pm, MP wrote:
Hello,

I have a Sony KV J 29MN1AK about 5 years old.

This TV has developed problems. It shows green colour lines slanted
towards right and spread across the entire screen. I have not
counted them, but these lines are mostly equally separated ( may be
about 1.5cms apart)

This seems to me a vertical flyback problem where the beams are not
blanked.

Can some experts in this forum help me to fix this problem ?

Do you have access to an oscilloscope and the schematic for the set??


H. R. (Bob) Hofmann


You shouldn't need either, I've been repairing things as a hobby for years,
I have a scope but rarely use it for repair, and schematics, those come once
in a blue moon, but usually it's just old fashioned intuition and a
multimeter. Look for a shorted transistor in the green drive circuit,
probably not the one directly connected to the green cathode or the whole
picture would have a green haze to it, but look further down the line,
closer to the video processing section.

Today, I opened the TV. Here are some of my experiements

I could locate the G2 pot on the PBC on the screen neck. I tried to
vary the G2 and clockwise movement helped to make these lines a bit
more lighter but then the TV takes about 1 minute to show the picture
whereas sound comes out immediately. I did some trial and error and
have kept the setting that reduces the lines a bit but takes about 30
to 45 sec for the picture to appear on the screen.

Can someon help me with the schematic and service manual ? I dont know
how to find the chassis number, but this is what I could read on all
the boards

There is a sticker on the CRT that says KV-29JMN1AK SCC-K67PA CHA NO
0705200

There is a rectangular board that says F2 Sony 1-670-752-12 F2601
T4.0A250V

The largest mother board has following written on it 1-666-699-21
There is a very large "A" printed on the board

The PCB on the neck of the CRT has following NE M PF2 1-656-470-15
(1-710-283-15)

My email is

"MP" wrote in message
...
Today, I opened the TV. Here are some of my experiements

I could locate the G2 pot on the PBC on the screen neck. I tried to
vary the G2 and clockwise movement helped to make these lines a bit
more lighter but then the TV takes about 1 minute to show the picture
whereas sound comes out immediately. I did some trial and error and
have kept the setting that reduces the lines a bit but takes about 30
to 45 sec for the picture to appear on the screen.

Can someon help me with the schematic and service manual ? I dont know
how to find the chassis number, but this is what I could read on all
the boards



Trace out the green video amp, try disconnecting the wire carrying the green
video from the main board to the neck board by removing the solder from the
pin and see if the green lines dissappear. If you can narrow down which
board the problem is on, you'll make things easier.

On Nov 26, 12:50 am, "James Sweet" wrote:
"MP" wrote in message

...

Today, I opened the TV. Here are some of my experiements

I could locate the G2 pot on the PBC on the screen neck. I tried to
vary the G2 and clockwise movement helped to make these lines a bit
more lighter but then the TV takes about 1 minute to show the picture
whereas sound comes out immediately. I did some trial and error and
have kept the setting that reduces the lines a bit but takes about 30
to 45 sec for the picture to appear on the screen.

Can someon help me with the schematic and service manual ? I dont know
how to find the chassis number, but this is what I could read on all
the boards

Trace out the green video amp, try disconnecting the wire carrying the green
video from the main board to the neck board by removing the solder from the
pin and see if the green lines dissappear. If you can narrow down which
board the problem is on, you'll make things easier.


Sure I will do this. Another thing I noticed. About an year back,
this TV had developed a problem. The sony technician said he would do
direct connection of the CRT tube. I see that he has taken a simple
wire with insulation, wound about 4 to 5 turns around the Flyback
arm. One wire end is soldered to the H pin ( I think it was H-) on
the CRT neck board. This H pin is one of the 13pins that hook into
the CRT.....and other wire is soldered to a resistor very near to the
H- pin. one end of the resistor is on the board and the other end is
removed and connected to this wire. Not sure what this arrangement
was for....

I know, the above is more english and less technical, but thats all i
could see there.... can anyone pls help me to understand what the
technician tried to do here ?


After 6 months of the above repair, the TV again developed problems
where there are no green colour. He changed the IC8575A and it worked
perfectly. ( I brought a new IC from market, placed it myself, but
the problem did not solve. The technician then took away the board,
removed my new IC and he put another IC and according to him, the
problem was solved... but i am not ready to believe him... when I
soldered my new IC, i had put a IC base,,, but this guy removed my IC
base and solved his IC back on the board.... somehow I feel that my
original IC was good and there was some resistor/capacitor faulty in
the path... :-)

"MP" wrote in message
...
On Nov 26, 12:50 am, "James Sweet" wrote:
"MP" wrote in message

...

Today, I opened the TV. Here are some of my experiements

I could locate the G2 pot on the PBC on the screen neck. I tried to
vary the G2 and clockwise movement helped to make these lines a bit
more lighter but then the TV takes about 1 minute to show the picture
whereas sound comes out immediately. I did some trial and error and
have kept the setting that reduces the lines a bit but takes about 30
to 45 sec for the picture to appear on the screen.

Can someon help me with the schematic and service manual ? I dont know
how to find the chassis number, but this is what I could read on all
the boards

Trace out the green video amp, try disconnecting the wire carrying the
green
video from the main board to the neck board by removing the solder from
the
pin and see if the green lines dissappear. If you can narrow down which
board the problem is on, you'll make things easier.


Sure I will do this. Another thing I noticed. About an year back,
this TV had developed a problem. The sony technician said he would do
direct connection of the CRT tube. I see that he has taken a simple
wire with insulation, wound about 4 to 5 turns around the Flyback
arm. One wire end is soldered to the H pin ( I think it was H-) on
the CRT neck board. This H pin is one of the 13pins that hook into
the CRT.....and other wire is soldered to a resistor very near to the
H- pin. one end of the resistor is on the board and the other end is
removed and connected to this wire. Not sure what this arrangement
was for....

I know, the above is more english and less technical, but thats all i
could see there.... can anyone pls help me to understand what the
technician tried to do here ?




He's isolated the heater, suspecting a heater to cathode short inside the
electron gun. It's quite possible that your problem is in fact a faulty
picture tube.

On Mon, 26 Nov 2007 20:33:47 GMT, "James Sweet"
wrote:


"MP" wrote in message
...
On Nov 26, 12:50 am, "James Sweet" wrote:
"MP" wrote in message

...

Today, I opened the TV. Here are some of my experiements

I could locate the G2 pot on the PBC on the screen neck. I tried to
vary the G2 and clockwise movement helped to make these lines a bit
more lighter but then the TV takes about 1 minute to show the picture
whereas sound comes out immediately. I did some trial and error and
have kept the setting that reduces the lines a bit but takes about 30
to 45 sec for the picture to appear on the screen.

Can someon help me with the schematic and service manual ? I dont know
how to find the chassis number, but this is what I could read on all
the boards

http://www.justmanuals.com



Trace out the green video amp, try disconnecting the wire carrying the
green
video from the main board to the neck board by removing the solder from
the
pin and see if the green lines dissappear. If you can narrow down which
board the problem is on, you'll make things easier.


Sure I will do this. Another thing I noticed. About an year back,
this TV had developed a problem. The sony technician said he would do
direct connection of the CRT tube. I see that he has taken a simple
wire with insulation, wound about 4 to 5 turns around the Flyback
arm. One wire end is soldered to the H pin ( I think it was H-) on
the CRT neck board. This H pin is one of the 13pins that hook into
the CRT.....and other wire is soldered to a resistor very near to the
H- pin. one end of the resistor is on the board and the other end is
removed and connected to this wire. Not sure what this arrangement
was for....

I know, the above is more english and less technical, but thats all i
could see there.... can anyone pls help me to understand what the
technician tried to do here ?




He's isolated the heater, suspecting a heater to cathode short inside the
electron gun. It's quite possible that your problem is in fact a faulty
picture tube.