Vertical deflection problems with Philips/Magnavox 27TS57C1

[Dan Rasmussen]

Hello,

I own a Philips 27TS57C1 TV with intermittent collapsing vertical
delection. The bottom half of the picture seems to collapsing to a
single line or shrinking into the top half. This happens briefly
several times a minute after warm up.

I have been reading up a bit on this problem and I have seen talk of a
service bulletin that may apply to this set. Can someone suggest
where I might find it. Where to get/order schematics for this set and
a good place to order parts. It sounds like I have a bad IC and maybe
some nearby parts. Might there be a Philips vertical deflection
problems kit available somewhere?

I don't normally work on TV's but have worked on 80's arcade monitors,
pinball tables, and older tube radios. It would be nice if I could
get this TV working to demonstrate to the wife that all the time/$$
spent on radios/games is finally paying off.

Thanks for any help/pointers.

Dan Rasmussen

 

[Sofie]

Dan Rasmussen:
Due to the intermittent nature of the vertical collapse that you described I
would confidently guess that the problem is caused by cracked, cold or
otherwise faulty solder connections near and around the vertical deflection
circuitry and most likely NOT caused by faulty components yet.... HOWEVER,
if you continue to operate the television with this problem it could easily
turn into a much more involved repair with necessary defective parts
replacement, so get this to a repair shop right away for what should be a
fairly routine and economical repair.
There is no need to order expensive schematics or an upgrade kit at this
point.... as the affected area of circuitry is easily identifiable by anyone
even vaguely knowledgeable and experienced with television repair .....
most shop techs will easily fix this by inspecting and resoldering the
faulty solder connections without the aid of schematics or replacement
parts.
Be advised that there are dangerous and lethal electrical shock hazards
inside your television..... furthermore, these hazards may still be present
even when the television is turned off and unplugged from the AC power....
the inside of a television is no place to learn electronics repair.
Get it to a shop right away.... do not keep operating the television with
this problem or the repair will be more costly. At the very least you
should TAKE it to a service shop for a repair cost estimate so you can make
an intelligent repair decision with facts instead of internet or telephone
guesses.
--
Best Regards,
Daniel Sofie
Electronics Supply & Repair
---------------------------



"Dan Rasmussen" <sscanf@yahoo.com> wrote in message
news:d0217809.0310221815.3ba59bea@posting.google.com...

Hello,

I own a Philips 27TS57C1 TV with intermittent collapsing vertical
delection. The bottom half of the picture seems to collapsing to a
single line or shrinking into the top half. This happens briefly
several times a minute after warm up.

I have been reading up a bit on this problem and I have seen talk of a
service bulletin that may apply to this set. Can someone suggest
where I might find it. Where to get/order schematics for this set and
a good place to order parts. It sounds like I have a bad IC and maybe
some nearby parts. Might there be a Philips vertical deflection
problems kit available somewhere?

I don't normally work on TV's but have worked on 80's arcade monitors,
pinball tables, and older tube radios. It would be nice if I could
get this TV working to demonstrate to the wife that all the time/$$
spent on radios/games is finally paying off.

Thanks for any help/pointers.

Dan Rasmussen

 

[Dan Rasmussen]

"Sofie" <sofie@olypen.com> wrote in message news:<vpej2s7771eoe2@corp.supernews.com>...

There is no need to order expensive schematics or an upgrade kit at this
point.... as the affected area of circuitry is easily identifiable by anyone
even vaguely knowledgeable and experienced with television repair .....

I haven't opened the set up yet, I am looking for some information
before I do. Having worked on video monitors in the past, I am
familiar with the safety issues and how to make the set safe to work
on. I wanted the schematics to help find the vertical deflection
section of the board. I realize that these sets are more complicated
and the boards are denser than the 80's era arcade monitors I have
worked on (most of my time has been spent on Wells-Gardner and
Amplifone Vector monitors) but it seems like those skills should apply
here. If they don't, please let me know why and I'll have to
reconsider.

Can someone give me some tips on how to home in on the vertical
deflection section of the board for this set (e.g. Look for chip X,
its silk screened on the board, trace back from the yoke, southwest of
the big heat sink, etc.). For those who have worked with these
sets/problems, will the problem area jump out at me (burn marks,
discolored board, delamination, arcing) or will I need to get my
magnifying glass out? Will I need to get my scope out? Am I just
going to wind up resoldering/touching up everything in that vertical
deflection section? Should I replace some electrolytic caps while I'm
there? This set is about six years old and performs well otherwise.

If I need to get the scope out, is it possible to run the set w/o HV
for diagnosis? If so, is it obvious how the HV is disconnected? On
the old vector monitors you could run with the HV cage unplugged.

I'm still curious about the service bulletin.

Thanks for any help.

Dan Rasmussen

 

[Sofie]

Dan Rasmussen:
Read again the reply post I sent to you......
No, you probably will NOT need to replace parts, replace electrolytics, make
adjustments, disconnect the high voltage, run the set without the HV
connected during diagnosis, get your scope out, randomly solder every
connection on the board, etc, etc...
instead, as my previous reply to you said, more than likely there are
cracked, cold or otherwise faulty solder connections in the vertical
deflection output circuitry......
look for "chip x, trace back from the yoke, southwest of the big heatsink,
etc" All that is needed is your soldering iron and some television repair
experience.
You might want to go to the website for this newsgroup at
http://www.repairfaq.org/
there with some searching you will find a wealth of information.
--
Best Regards,
Daniel Sofie
Electronics Supply & Repair
--------------------------------


"Dan Rasmussen" <sscanf@yahoo.com> wrote in message
news:d0217809.0310230447.6e539cf@posting.google.com...

"Sofie" <sofie@olypen.com> wrote in message
news:<vpej2s7771eoe2@corp.supernews.com>...
There is no need to order expensive schematics or an upgrade kit at this
point.... as the affected area of circuitry is easily identifiable by
anyone
even vaguely knowledgeable and experienced with television repair .....

I haven't opened the set up yet, I am looking for some information
before I do. Having worked on video monitors in the past, I am
familiar with the safety issues and how to make the set safe to work
on. I wanted the schematics to help find the vertical deflection
section of the board. I realize that these sets are more complicated
and the boards are denser than the 80's era arcade monitors I have
worked on (most of my time has been spent on Wells-Gardner and
Amplifone Vector monitors) but it seems like those skills should apply
here. If they don't, please let me know why and I'll have to
reconsider.

Can someone give me some tips on how to home in on the vertical
deflection section of the board for this set (e.g. Look for chip X,
its silk screened on the board, trace back from the yoke, southwest of
the big heat sink, etc.). For those who have worked with these
sets/problems, will the problem area jump out at me (burn marks,
discolored board, delamination, arcing) or will I need to get my
magnifying glass out? Will I need to get my scope out? Am I just
going to wind up resoldering/touching up everything in that vertical
deflection section? Should I replace some electrolytic caps while I'm
there? This set is about six years old and performs well otherwise.

If I need to get the scope out, is it possible to run the set w/o HV
for diagnosis? If so, is it obvious how the HV is disconnected? On
the old vector monitors you could run with the HV cage unplugged.

I'm still curious about the service bulletin.

Thanks for any help.

Dan Rasmussen

 

[Dan Rasmussen]

I pulled the chassis and inspected for cracks, cold joints, etc. No
problems found. One IC looked toasted: STV9379FA, Vertical deflection
booster. Resoldered it and other related high current components, no
change (vertical deflection problems remained).

Orderered new STV9379FA (must be FA variant, STV9379 not compatible)
from http://www.tritronicsinc.com/ installed, problem solved.

Thanks for the help.

Dan Rasmussen


sscanf@yahoo.com (Dan Rasmussen) wrote in message news:<d0217809.0310221815.3ba59bea@posting.google.com>...

Hello,

I own a Philips 27TS57C1 TV with intermittent collapsing vertical
delection. The bottom half of the picture seems to collapsing to a
single line or shrinking into the top half. This happens briefly
several times a minute after warm up.

I have been reading up a bit on this problem and I have seen talk of a
service bulletin that may apply to this set. Can someone suggest
where I might find it. Where to get/order schematics for this set and
a good place to order parts. It sounds like I have a bad IC and maybe
some nearby parts. Might there be a Philips vertical deflection
problems kit available somewhere?

I don't normally work on TV's but have worked on 80's arcade monitors,
pinball tables, and older tube radios. It would be nice if I could
get this TV working to demonstrate to the wife that all the time/$$
spent on radios/games is finally paying off.

Thanks for any help/pointers.

Dan Rasmussen