Fallen TV - no picture, sound OK

[Tony Ramone]

Hi all, I tried posting this back in my original thread, but I can't
for some reason (maybe it's too old or something), which is why I'm
pasting the original message in here, along with my follow up
question. Hope this isn't a horrible breach of usenetiquette...

Thanks, I hadn't seen that, sorry. And thanks for all the tips
everyone else.

(and now the follow up):

I know it's been many months since I last posted on this, but
I just thought I'd check with you guys one last time before consigning
this TV to the dump.
Having read all your posts, and the FAQ, I looked around the board for
any cracks, and lo and behold, there was quite a sizeable one running
close to what I assume is the flyback transformer. And sure enough it
was running right through a fairly big track.
So I fixed the crack, then ran some solder and a thin wire along the
broken track. I checked it with my multimeter to make sure I had a
good connection between either end.
The thing is, it's still not working, and I noticed that one of the
smaller components near the transformer looks a little burnt (or at
least brown - could just be flux i suppose) on the underside (I'll
have to check again later which part it was - I can't find the piece
of paper that I had written it down on right now), and I guess it
could be that, or else maybe the transformer itself is just fucked.
If that's the case is it worth my while trying to fix it at all
(bearing in mind that while I do know how to solder and read circuit,
I don't really know what's going on on that particular board ).
I've already gotten a replacement, but I figured if this one would be
an easy fix I'd keep it for the spare room, but if not, then so be
it...
Thanks again for all your patience.

Ant

 

[Samuel M. Goldwasser]

Hi all, I tried posting this back in my original thread, but I can't
for some reason (maybe it's too old or something), which is why I'm
pasting the original message in here, along with my follow up
question. Hope this isn't a horrible breach of usenetiquette...

(and now the follow up):

I know it's been many months since I last posted on this, but
I just thought I'd check with you guys one last time before consigning
this TV to the dump.
Having read all your posts, and the FAQ, I looked around the board for
any cracks, and lo and behold, there was quite a sizeable one running
close to what I assume is the flyback transformer. And sure enough it
was running right through a fairly big track.
So I fixed the crack, then ran some solder and a thin wire along the
broken track. I checked it with my multimeter to make sure I had a
good connection between either end.
The thing is, it's still not working, and I noticed that one of the
smaller components near the transformer looks a little burnt (or at
least brown - could just be flux i suppose) on the underside (I'll
have to check again later which part it was - I can't find the piece
of paper that I had written it down on right now), and I guess it
could be that, or else maybe the transformer itself is just fucked.
If that's the case is it worth my while trying to fix it at all
(bearing in mind that while I do know how to solder and read circuit,
I don't really know what's going on on that particular board ).
I've already gotten a replacement, but I figured if this one would be
an easy fix I'd keep it for the spare room, but if not, then so be
it...

It's possible that something else blew when it was run with the crack.

ButI wouldn't be surprised if there are more fine cracks that you
simply haven't noticed going through other tracks.\

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[Mark Zacharias]

It's possible that something else blew when it was run with the crack.

ButI wouldn't be surprised if there are more fine cracks that you
simply haven't noticed going through other tracks.\

Still, the OP probably should not be into this. The high voltage section of
a TV is no place for newbies, especially when we already know he does not
possess the requisite soldering and related skills.

Mark Z.

 

[Tony Ramone]

Still, the OP probably should not be into this. The high voltage section of
aTVis no place for newbies, especially when we already know he does not
possess the requisite soldering and related skills.

Mark Z.

What's wrong with my soldering skills? I solder every day, just not
TVs.

 

[b]

So I fixed the crack, then ran some solder and a thin wire along the
broken track. I checked it with my multimeter to make sure I had a
good connection between either end.
The thing is, it's still not working,

I have worked on dropped tvs many times. as others here have said,
chances are you have more cracks. i've been caught out like that
before.

Also, I have had the pcb flex on landing and some transistors and
regulators worked loose from their solder pads. That was on a Hitachi
28" widescreen set. look for heavier components , transformers,
heatsinked stuff. BTW I think the brown component you mention may be a
red herring. I'd look elsewhere first and come back to that later.

check the pcb on the tube also, in case.

keep at it
-b

 

[Franc Zabkar]

I have worked on dropped tvs many times. as others here have said,
chances are you have more cracks. i've been caught out like that
before.

Also, I have had the pcb flex on landing and some transistors and
regulators worked loose from their solder pads. That was on a Hitachi
28" widescreen set. look for heavier components , transformers,
heatsinked stuff. BTW I think the brown component you mention may be a
red herring. I'd look elsewhere first and come back to that later.

check the pcb on the tube also, in case.

keep at it
-b

I'd also drill a hole at the ends of each track, components and traces
permitting. This will relieve any stress and prevent cracks from
propagating.

- Franc Zabkar

 

[Franc Zabkar]

Novel concept. While this may be good practice on a single material PCBs
are composites, and it's usually just the track that cracks. And by nature
tends to be across the entire track so can't spread anymore.

Sorry, I should have written, "drill a hole at the ends of each
crack", not track. My former boss always insisted on this.

- Franc Zabkar

 

[Tony Ramone]

Sorry, I should have written, "drill a hole at the ends of each
crack", not track. My former boss always insisted on this.

- Franc Zabkar
--

Ha, the drummer in my band does the same thing to cracked cymbals. It
works though. Thanks for all the new tips guys. Hopefully I'll get to
have another look at it this weekend.

 

[Tony Ramone]

I have worked on dropped tvs many times. as others here have said,
chances are you have more cracks. i've been caught out like that
before.

Also, I have had the pcb flex on landing and some transistors and
regulators worked loose from their solder pads. That was on a Hitachi
28" widescreen set. look for heavier components , transformers,
heatsinked stuff. BTW I think the brown component you mention may be a
red herring. I'd look elsewhere first and come back to that later.

 check the pcb on the tube also, in case.

keep at it
-b

OK, so I finally had a chance to have one last look at it a couple of
weekes ago before deciding to throw it out and, sure enough, there
were a few more cracks that I hadn't seen the first time round (the
lighting in the room it was in is fairly bad).
So I got out my tools again, patched it up, plugged it in, stood back
and, with a long stick in hand (maybe overly cautious ), switched it
on. Badda-bing, badda-boom - I've got a picture.
So I'd just like to say thanks to everyone here for all the helpful
tips, it's much appreciated.
Cheers,
ANT

 

[b]

OK, so I finally had a chance to have one last look at it a couple of
weekes ago before deciding to throw it out and, sure enough, there
were a few more cracks that I hadn't seen the first time round (the
lighting in the room it was in is fairly bad).
So I got out my tools again, patched it up, plugged it in, stood back
and, with a long stick in hand (maybe overly cautious ), switched it
on. Badda-bing, badda-boom - I've got a picture.
So I'd just like to say thanks to everyone here for all the helpful
tips, it's much appreciated.
Cheers,
ANT

well done -persistence usually pays off with these things!
-B