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TV shows stripes/lines at the top of the screen

T

Tech Data

Jan 1, 1970
0
-Almazick- said:
Hello!
I have Panasonic TV about 1 year old. It was working great til a few weeks
ago, now it shows stripes/lines at the top of the screen that used to get
better after tv was getting warm. Now I got more stripes/lines at the top of
the screen and they don't dissapear even when tv gets warm. I removed the tv
rear cover and found only 2 knobs for Focus and Screen and they won't solve
the problem. I tried to adjust Var Resistor and again nothing. What can I
do? What should I check for? Please help.

Thanks,

Almazick
www.tvnorthshore.com


"What should I check for?" The nearest servicer in the Yellow Pages and
ask them what they'd charge to correct this. If the first and only
thing you try is to turn things that move to repair this, then guiding
you to the probable circuit would most likely turn the tv into dumpster
fodder. That's a nice product. Spend a little and get it fixed right.

www.techdata-kicksass.net
 
A

-Almazick-

Jan 1, 1970
0
Hello!
I have Panasonic TV about 1 year old. It was working great til a few weeks
ago, now it shows stripes/lines at the top of the screen that used to get
better after tv was getting warm. Now I got more stripes/lines at the top of
the screen and they don't dissapear even when tv gets warm. I removed the tv
rear cover and found only 2 knobs for Focus and Screen and they won't solve
the problem. I tried to adjust Var Resistor and again nothing. What can I
do? What should I check for? Please help.

Thanks,

Almazick
www.tvnorthshore.com
 
A

-Almazick-

Jan 1, 1970
0
Thanks for your response but it's not what I'm looking for. I'm looking for
help and to point me to the right direction. If I wanted to give it to
service I would done it a long time ago but that's no fun at all. That's
the idea to learn it and do it yourself. Also If I had no idea what I was
doing I wouldn't even touch it but I've done in the past couple of projects
creating PCB and making IC to work. It's all about fun and enjoying what
you are doing. This is diy electronics repair forum and people expect to
get help to solve the problem not to create another one just like you
advised it and please next time stay on the subject and don't create another
one.
 
A

Arfa Daily

Jan 1, 1970
0
-Almazick- said:
Thanks for your response but it's not what I'm looking for. I'm looking
for help and to point me to the right direction. If I wanted to give it
to service I would done it a long time ago but that's no fun at all.
That's the idea to learn it and do it yourself. Also If I had no idea
what I was doing I wouldn't even touch it but I've done in the past couple
of projects creating PCB and making IC to work. It's all about fun and
enjoying what you are doing. This is diy electronics repair forum and
people expect to get help to solve the problem not to create another one
just like you advised it and please next time stay on the subject and
don't create another one.
It is a nice idea that you would like to fix it yourself, but I have to say
that the advice that you were given by Tech Data, in this case, was valid
for your own safety, if nothing else. Modern TV sets are DANGEROUS items -
probably more so than their predecessors. They all utilise switch mode power
supplies, and if you do not understand these, or work with them on a regular
basis, and have a proper transformer-isolated safety supply to run them
from, then they can be lethal - and I mean that by the most death-causing
literal definition that you can find.

Creating PCBs, and making ICs work do not, unfortunately, qualify you to be
poking around safely in the back of a TV. Even twiddling the screen pot,
without knowing what it does, or how to readjust it correctly so that you
don't have a useless CRT on your hands in a couple of months, to add further
to your woes, indicates that you should not be attempting this.

Whilst this is a DIY repair group, for some types of repair, a degree of
expertise is still required, and in our opinion, you simply don't have the
necessary expertise to be attempting a repair such as this. Those of us who
do, would be irresponsible to advise you to try, for your own safety. The
advice you were given was good, and I think the same as most of us would
have given - take it to a reputable repair shop. If you really don't want to
spend the money on it, and it really is just a year old, then pick up the
phone and bleat long and hard to Panasonic's customer liason - you might
just get a result, and live long enough to enjoy it ...

Also, if you wouldn't mind, please don't top-post. It makes threads
difficult to follow once they get above a couple long.

Arfa
 
T

Tech Data

Jan 1, 1970
0
-Almazick- said:
Thanks for your response but it's not what I'm looking for. I'm looking for
help and to point me to the right direction. If I wanted to give it to
service I would done it a long time ago but that's no fun at all. That's
the idea to learn it and do it yourself. Also If I had no idea what I was
doing I wouldn't even touch it but I've done in the past couple of projects
creating PCB and making IC to work. It's all about fun and enjoying what
you are doing. This is diy electronics repair forum and people expect to
get help to solve the problem not to create another one just like you
advised it and please next time stay on the subject and don't create another
one.

Wow, thanks for putting me in my place. Did you realize that you posted
twice and, by omission, indicate that you think Panasonic made only one
television, ever, and you own it? If you expect someone to lead you to
a magic fix, you might want to post a model number or, at the very
least, a color.
 
S

Sam Goldwasser

Jan 1, 1970
0
Tech Data said:
"What should I check for?" The nearest servicer in the Yellow Pages and
ask them what they'd charge to correct this. If the first and only
thing you try is to turn things that move to repair this, then guiding
you to the probable circuit would most likely turn the tv into dumpster
fodder. That's a nice product. Spend a little and get it fixed right.

www.techdata-kicksass.net

The problem is likely a bad capacitor in the vertical deflection output.

But I agree - get it fixed by a professional and DON'T touch any of the
internal adjustments! This is a circuit failure.

--- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.
 
D

Dave D

Jan 1, 1970
0
-Almazick- said:
Thanks for your response but it's not what I'm looking for. I'm looking
for help and to point me to the right direction. If I wanted to give it
to service I would done it a long time ago but that's no fun at all.
That's the idea to learn it and do it yourself. Also If I had no idea
what I was doing I wouldn't even touch it but I've done in the past couple
of projects creating PCB and making IC to work. It's all about fun and
enjoying what you are doing. This is diy electronics repair forum and
people expect to get help to solve the problem not to create another one
just like you advised it and please next time stay on the subject and
don't create another one.

If you'd provided a model number and resisted the temptation to indulge in
dangerous buffoonery, then maybe the *group* (this is *not* a forum!) would
have considered you had enough credibility to undertake a repair. However,
by your actions you have demonstrated that the only successful undertaking
will be your subsequent funeral.

You clearly do not understand televisions or their circuits and adjustments,
and I'm certain few people would recommend you learn the craft with a good,
newish TV when they know full well you may injure/kill yourself or wreck the
TV. Seriously- anyone who thinks the 'focus' control will cure lines at the
top of the screen has no business inside a TV set- even my 13 year old
daughter knows what 'focus' means ;-)

Furthermore, a basic rule of repair is that adjusting things when a fault
arises is a no-no. Apart from the simple fact that it rarely helps to effect
a good repair, it will at best mask the fault, and at worst make a simple
repair into a realignment job which increases the total repair cost. Worse
still you randomly adjusted settings you didn't understand- what did you
hope to achieve? Would you randomly adjust things on your car's carburettor
if the tail light developed a fault?

If you want to learn TV repair, I recommend you get a good book and
understand how they work before you go inside and practice, you and the TV
will live longer.

The answer to your question is electrolytic capacitors in the vertical
deflection circuit as Sam stated- about 99% certainty. It's not an expensive
job and straightforward enough for a half decent tech, so I recommend you
pay to get it done.

As for wanting to fix it yourself as part of a learning process, learning
what exactly? You had to come here to ask where the fault was, so the hard
part has been answered for you. The remainder of the job is soldering in
replacements, far better you practice soldering on a scrap PCB than a year
old TV.

Good luck with your TV, and stay alive!

Dave
 
A

-Almazick-

Jan 1, 1970
0
Thanks a lot for the answer. Sorry for not posting the model because I did
not think it was very important just because it is a general problem. I
spent all night reading tv problems and found similar problem with the same
answer. I was wondering where can I get Service Manual for Panasonic
CT-24SL14J or just a schematic to find bad capacitor in the vertical
deflection? I checked IC yesterday but I couldn't find a bad capacitor by
an eye. Regarding safety I do understand it is very dangerous to put your
fingers inside of the tv because of the High Voltage unless your discharge
capacitors or follow safety code. I learned my lesson a long time ago. I
do know what I'm doing and it is not the first time. I also understand that
I don't have enough experience but again it is all about learning.
 
F

Franc Zabkar

Jan 1, 1970
0
Thanks a lot for the answer. Sorry for not posting the model because I did
not think it was very important just because it is a general problem. I
spent all night reading tv problems and found similar problem with the same
answer. I was wondering where can I get Service Manual for Panasonic
CT-24SL14J or just a schematic to find bad capacitor in the vertical
deflection? I checked IC yesterday but I couldn't find a bad capacitor by
an eye.

Look for an IC on a heatsink, possibly an LAxxxx type. Then download
its datasheet and study the application circuit therein. You will see
several electrolytic capacitors. You may as well change all of them -
they are cheap enough.

BTW, in Australia you would be entitled to a free warranty repair on
the grounds that your one year old (?) TV is not of merchantable
quality. This is despite the fact that the manufacturer's voluntary
warranty is only 1 year.

- Franc Zabkar
 
D

Dave D

Jan 1, 1970
0
-Almazick- said:
Thanks a lot for the answer. Sorry for not posting the model because I
did not think it was very important just because it is a general problem.
I spent all night reading tv problems and found similar problem with the
same answer. I was wondering where can I get Service Manual for Panasonic
CT-24SL14J or just a schematic to find bad capacitor in the vertical
deflection? I checked IC yesterday but I couldn't find a bad capacitor by
an eye.


By eye? No good in this case. Testing with an ESR meter or substitution is
the way to do it. If in doubt, just change all the electrolytic capacitors
in the vertical deflection area, they aren't expensive parts and it could
prevent further trouble.

Dave
 
A

-Almazick-

Jan 1, 1970
0
Great I found everything already. Instead of LA4845 it is using AN15525 IC.
In datasheet it shows 3 caps in example schematic. I'll try to replace on
tuesday some of my caps in my tv. Really bad that I don't have ESR meter
should make my job a lot easier :) again thanks a lot.
 
J

JANA

Jan 1, 1970
0
Troubleshoot the set for defective components in the vertical deflection
area. It is impossible to guess to the exact components. There are many
involved. You will require at the very least, a DVM, ESR meter, and the
service manuals for your set. If the problem gets complicated, you will need
a scope. Also, it is an asset to have the proper training in electronics,
and in TV servicing.

Your best solution is to bring the set to a service centre and have them
service it for you. There are also serious safety issues when servicing TV
sets and electrical appliances.

--

JANA
_____



-Almazick- said:
Hello!
I have Panasonic TV about 1 year old. It was working great til a few weeks
ago, now it shows stripes/lines at the top of the screen that used to get
better after tv was getting warm. Now I got more stripes/lines at the top
of
the screen and they don't dissapear even when tv gets warm. I removed the
tv
rear cover and found only 2 knobs for Focus and Screen and they won't
solve
the problem. I tried to adjust Var Resistor and again nothing. What can I
do? What should I check for? Please help.

Thanks,

Almazick
www.tvnorthshore.com


"What should I check for?" The nearest servicer in the Yellow Pages and
ask them what they'd charge to correct this. If the first and only
thing you try is to turn things that move to repair this, then guiding
you to the probable circuit would most likely turn the tv into dumpster
fodder. That's a nice product. Spend a little and get it fixed right.

www.techdata-kicksass.net
 
E

Electromotive Guru

Jan 1, 1970
0
Okay if the rest of you all are done with your immature flame war,
can say through all my experience that is is definitely a ba
capacitor either in the vertical or power supply area. No cap shoul
be getting too hot, so this may be a symptom of the main voiltag
bias being out of range. Look inwside the back cover for test-point
and check that main B+ voltage is within 5% of spec (if given)

So the guy wants to learn, noone becomes an expert from a book alone
If any of you people flaming were experts, you should already kno
that. While I agree that diagnosis comes before adjustments, and tha
some skill is required, he IS NOT FIXING YOUR EQUIPMENT, so get ove
it. If they do something wrong, it's on them, not you, in case yo
forgot...

Sheesh, seems people here are a bit too uppity about things that the
have made into their own personal problem. Quit shutting out someon
with an idea, everyone has to make mistakes to learn. You could al
suggest politely that the focus control will not fix it. For thos
who want to know, I am self-taught on many a different area that yo
will never understand, and know more in many than all the book-smart
in the world

8 years of college cannot teach what I have learned in as little a
five seconds..
 
A

Arfa Daily

Jan 1, 1970
0
Electromotive Guru said:
Okay if the rest of you all are done with your immature flame war, I
can say through all my experience that is is definitely a bad
capacitor either in the vertical or power supply area. No cap should
be getting too hot, so this may be a symptom of the main voiltage
bias being out of range. Look inwside the back cover for test-points
and check that main B+ voltage is within 5% of spec (if given).

So the guy wants to learn, noone becomes an expert from a book alone.
If any of you people flaming were experts, you should already know
that. While I agree that diagnosis comes before adjustments, and that
some skill is required, he IS NOT FIXING YOUR EQUIPMENT, so get over
it. If they do something wrong, it's on them, not you, in case you
forgot....

Sheesh, seems people here are a bit too uppity about things that they
have made into their own personal problem. Quit shutting out someone
with an idea, everyone has to make mistakes to learn. You could all
suggest politely that the focus control will not fix it. For those
who want to know, I am self-taught on many a different area that you
will never understand, and know more in many than all the book-smarts
in the world.

8 years of college cannot teach what I have learned in as little as
five seconds...

There is a difference between helping someone to learn safely, and being
irresponsible. By saying that he had attempted to 'repair' his faulty
television set, by twiddling controls whose function he understood nothing
about, the OP demonstrated that he was not competent to be inside a
television set with safety. Now you may think that is ok, but I think that
if those of us who are properly qualified, and whose collective wisdom
exceeds yours by many times, were to recommend that he continued to poke
around inside an item of equipment that REALLY COULD KILL OR SERIOUSLY
INJURE him, this would be irresponsible, rather than helpful.

For sure, we all learn by making mistakes, but you're not gonna learn a lot,
if your first bad one puts you in the mortuary. In order to learn repair of
TV sets, and similar equipment, safely, you need at least a mentor, who is
fully qualified, and standing by your side watching your every move. You
absolutely MUST understand the safety angles of what you are doing,
otherwise, with a couple of repair successes under your belt, you will start
to become a self-proclaimed self-taught *expert* who then goes on to carry
out dangerous work on other people's equipment.

Whilst it is possible for qualified people to learn new techniques and hints
and tips from groups such as this, it is not possible for total amateurs to
learn arts such as TV repair, safely. Would you seriously suggest that
someone should try SCUBA diving, or sky diving, or mountain climbing or
racecar driving, without having been practically taught by someone who knows
how to do it safely ? No, of course not, and anyone who believes seriously
that electricity is not equally dangerous, is a fool.

No one has been *flamed* on here. Perhaps one or two of the comments were a
little less than polite, but if you think that is flaming, then you have
lived a sheltered internet life. Everyone from amateurs to professionals are
welcome on here, and will normally recive good and valid advice, but don't
expect those of us who take a responsible attitude to safety, to encourage
either those who don't, or those who have no knowledge of such matters.

Arfa
 
D

Dave D

Jan 1, 1970
0
Now you may think that is ok, but I think that if those of us who are
properly qualified, and whose collective wisdom exceeds yours by many
times, were to recommend that he continued to poke around inside an item
of equipment that REALLY COULD KILL OR SERIOUSLY INJURE him, this would be
irresponsible, rather than helpful.


Now now, Arfa! 'Electromotive Guru' is obviously someone the group should
look up to. After all, he advises someone who knows so little about basic
physics that he doesn't know what a focus adjustment does, to, and I quote:

"Look inwside the back cover for test-points and check that main B+ voltage
is within 5% of spec" (because) "this may be a symptom of the main voiltage
bias being out of range"

Obviously good advice ;-) He also thinks it's good advice for a non-savvy
consumer to take the back off his set and poke around inside so he can
'learn', without having even the most basic knowledge of electronics.

By his reasoning- my 13 year old daughter knows what focus means, and it's
not just a car made by Ford, so she must be even more qualified than the OP
to poke around inside a TV! Next time the TV breaks I might give her a
service manual and a soldering iron and let her fix it for me. It's a nice
RPTV so plenty of room for her to crawl inside and measure the 'main bias
voltage'. I wouldn't want to deprive her of a learning experience after all!

Dave
 
A

-Almazick-

Jan 1, 1970
0
Hello Dave D,
I see your point regarding your 13 year old daughter knows what focus means
and that's good but you need to learn how to read first before you flame
anyone. If you read my original post you can find "I removed the tv rear
cover and found only 2 knobs for Focus and Screen and they won't solve the
problem." I do know what focus and screen means too but I did not say that
I was tweaking them or did not know what it was. What I meant that I found
only 2 knobs and it won't solve the problem because they have nothing to do
with the problem I had (vertical deflection output). In older tv's used to
be knobs behind the cover or small holes for vertical and horizontal
adjustments. You assumed that I did not know what focus is and made
something out of nothing. Anyway let's just stop arguing and stop putting
people down. If people ask for advice, let's just give them because you
don't know what they know and their experiences. Just like Electromotive
Guru said, him and me are self-taught on many a different area that you
won't have any idea how to fix it. In some areas I'm more stronger and some
weaker and when I ask people for advice who knows more than me I don't
really want to listen flames because I can bet you ask questions in other
boards and you don't want people flaming you. I used to be on boards a long
time ago helping people with cars, satellite dishes, operating systems,
computer hardware and web designers because I'm good at it but I never made
any flames. Don't like the question just go to the next one, simply ignore
them. People always make a mistake with a bad description just like I did
but it doesn't mean you are better than me because you really don't know me.
On the other hand I fixed the tv and it only took me about 30 minutes. As
you can see people it takes less time to fix something with a proper answer
than reading all that flaming and your bad opinions which makes me sick. If
you don't like something it doesn't mean you have to start flaming people
just ignore and go to the next post. It makes our life's a lot easier. A
big thanks to people who pointed me to the right direction: Sam Goldwasser,
Franc Zabkar, Jana and Electromotive Guru.
 
D

Dave D

Jan 1, 1970
0
-Almazick- said:
Hello Dave D,
I see your point regarding your 13 year old daughter knows what focus
means and that's good but you need to learn how to read first before you
flame anyone. If you read my original post you can find "I removed the tv
rear cover and found only 2 knobs for Focus and Screen and they won't
solve the problem."

<snip>

OK, I accept I have misunderstood you, but please understand that "and they
won't solve the problem." can also mean you tried them to no avail. Damn
the English language, ambiguity is too common!

I am sorry you didn't consider my advice to be helpful, and indeed
considered it to be flaming. However, we are not mind readers. How was I to
know you were techinically minded? You certainly didn't give that impression
from your OP which was vague and admitted lack of knowledge of the working
of TVs, and clearly I'm not the only one who thought that.

Generally, if people come here with intelligent questions and can provide
troubleshooting info, they will get intelligent answers. If they come here
and give the impression that they know nothing (as you did- you said you
wanted to learn) and ask questions like 'my TV went funny, which part do I
change?' (extreme example) then they will often be disappointed.

If you read back over my posts you'll find that in actual fact I did give an
answer, despite what you think. Furthermore, though it wasn't what you
wanted to hear, my advice to stay away from TVs until you get up to speed on
LV equipment was sound and I had your interests at heart. I could have said
'dive in with both hands while it's on, and make sure you're a bit damp',
but no- I was simply concerned for your safety. The advice was given based
on the impression of your abilities *you* created here, and I stand by it.

Anyhoo, no offence intended- it was just banter. Good luck with the repair.

Dave
 
P

Papa_J

Jan 1, 1970
0
Bottom Line: Did you get the set repaired as a result of the information you
collected or is it still broken.
PLEASE!! Forget or forgive the flack and debris??
Many of the folk here in this N/G have been around for a fairly long period
of time doing these repairs, inclusive of Sam, and many others.
Their main concern is for the SAFETY of the technicians, even SAM posts that
information plainly, at the beginning of his very good instructional web
sites.
After that fact then the appropriate data is attempted to be transferred via
this means, some if it is miss-interpreted, some if it is
miss-representative of the actual symptom(s). However all of it is normally
meant as trying to assist another technician to do their actual, hands on
repairs.
Ocassionally we all share our "Opinions", and we all acknowledge what the
average one's worth (IMHO).
Again: My specific question is: Do you have the set repaired? If so than you
have received assistance appropiat to your quest. If not, then more through
diagnostics may be required.
Good Luck!
 
A

-Almazick-

Jan 1, 1970
0
I fixed the tv by the information I received from Franc Zabkar. I found
datasheet then found similar schematic for my tv. Changed 1 capacitor
turned on the tv and everything was working.
 
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