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Soldering a Broken TV

Thanks to those of you that actually had helpful things to say.

I let the TV sit for 48 hours, cracked it open, and went in with the
soldering iron. Now all is well.

Responses like "Don't even try, you suck, you don't have the skills."
aren't helpful in teaching others new things. People aren't born with
these skills and neither were you. Offer some constructive advice to
help people to learn rather than put them down.
 
I started having trouble with my TV after it was moved in a U-Haul from
San Francisco to Seattle. I managed to locate a faulty solder joint on
the board. Applying pressure to the joint with a strip of wood fixes
the problem.

My problem is this: I am very experienced with electronics and
soldering, but I have little experience when it comes to high voltage.
I need to fix the solder joint but I have no hardware to properly
discharge any high voltage capacitors in the TV. I don't think this is
a problem as the faulty solder joint is attached to what appears to be
a FET. However, it could also be a triac, which could mean that it's
attached to a HV part of the circuit. I don't want to stick my head in
there to find out exactly what it is. Would you advise fixing the
solder joint without first discharging the TV?

Thanks in advance!


Always best to discharge! you can use a simple flathead screwdriver
with an alligator clip. Clip it to the screwdriver and clip it to DAG
Ground... it will be a braid of wire attached to the CRT tube slide
flathead screw driver in under the anode cap that runs to the flyback
transformer. It will look like a large suction cup attached to the
picture tube.. You will hear a 'pop' as the HV discharges. Then it will
be ready to pull that board. I would still be leary of the filter caps
though!
 
H

Homer J Simpson

Jan 1, 1970
0
Thanks to those of you that actually had helpful things to say.

I let the TV sit for 48 hours, cracked it open, and went in with the
soldering iron. Now all is well.

Responses like "Don't even try, you suck, you don't have the skills."
aren't helpful in teaching others new things. People aren't born with
these skills and neither were you. Offer some constructive advice to
help people to learn rather than put them down.

OK. Here is constructive advice. Learn the way I did - take a 5 year
apprenticeship and pass the required exams to become qualified.
 
Thanks to those of you that actually had helpful things to say.

I let the TV sit for 48 hours, cracked it open, and went in with the
soldering iron. Now all is well.

Responses like "Don't even try, you suck, you don't have the skills."
aren't helpful in teaching others new things. People aren't born with
these skills and neither were you. Offer some constructive advice to
help people to learn rather than put them down.

Some offered advice intended to avoid risk of death or injury to
yourself. Maybe it wasnt put the best way. Some of us have learnt the
painful way. Some are lucky to be alive today. Some have learnt the
hard way, and they cant give you the benefit of their experience any
more.

Sitting it for 2 days does not ensure discharge and does not mke it
safe to work on, I've drawn nice energetic sparks off a tv after a
week. Dischargng is easy to do.


NT
 
S

Sam Goldwasser

Jan 1, 1970
0
Homer J Simpson said:
OK. Here is constructive advice. Learn the way I did - take a 5 year
apprenticeship and pass the required exams to become qualified.

Sorry, that's not constructive advice in this context.

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K

Ken G.

Jan 1, 1970
0
Glad you got it fixed .. see that was easy .

The people who did not give a decent answer do not know the answer so
now they learn too .
 
H

Homer J Simpson

Jan 1, 1970
0
Sorry, that's not constructive advice in this context.

Sure it was. Some people are capable. Some are not. I've spent too much time
cleaning up after those who are not. One lucky break doesn't change my
views.
 
M

Michael Black

Jan 1, 1970
0
Ken said:
Glad you got it fixed .. see that was easy .

The people who did not give a decent answer do not know the answer so
now they learn too .

These little homilies don't do a thing.

The poster declared that he knew about electronics and soldering,
yet he neither knew how to discharge the CRT, or had the means of
looking it up.

That does not indicate someone who is well versed in electronics.

Now the interesting thing is that if he'd not put in that bit,
he might not have gotten the answers he did. Boastfulness often
doesn't result in help, it certainly doesn't result in sympathy.

And ultimately the boast didn't do a thing, because whether or
not he did know anything, he didn't know the bit he did need to know
(by his own acknowledgement, after all, he was asking how to discharge
the CRT). He couldn't have done any worse by not putting that bit
in.

All of this is reinforced when he comes back and thanks the people
he helped, and denounces those who didn't. That's part of the process.

It's not as if this hasn't happened before, by many other posters.

Michael
 
J

James Sweet

Jan 1, 1970
0
Homer said:
OK. Here is constructive advice. Learn the way I did - take a 5 year
apprenticeship and pass the required exams to become qualified.


Or just jump in and start working on things like I did, with the
internet, who needs to waste 5 years taking a course?
 
Always best to discharge! you can use a simple flathead screwdriver
with an alligator clip. Clip it to the screwdriver and clip it to DAG
Ground... it will be a braid of wire attached to the CRT tube slide
flathead screw driver in under the anode cap that runs to the flyback
transformer. It will look like a large suction cup attached to the
picture tube.. You will hear a 'pop' as the HV discharges. Then it will
be ready to pull that board. I would still be leary of the filter caps
though!

This is not safe.

1. Alligator clips come off very readily, and screwdrivers dont
insulate to 25kV. There is also the q of what the clip is touching
after its come off, it may be your metal trouser fly. :)
2. The OP may think you mean the braid that connects to the tube base
pcb, and aquadag braid to chassis is prone to coming disocnnected in
some set designs, so again this may fail at times.
3. Finally a single zap does not discharge the CRT, it typically takes
3 goes.
4. And lastly, reservoir caps must be discharged too. They are a good
deal more dangerous than CRT EHT, which is usualy not fatal and is more
or less insulated. Reservoirs OTOH are kill capable, and conductive
paths route their energy to who knows where on the board. And typically
a repair will involve handling the main board - often with both hands,
which is where the danger comes in. A cap full of 330v across the 2
hands is not something to volunteer for.

Maybe the OP should read up on Darwin Awards.


NT
 
J

James Sweet

Jan 1, 1970
0
This is not safe.

1. Alligator clips come off very readily, and screwdrivers dont
insulate to 25kV. There is also the q of what the clip is touching
after its come off, it may be your metal trouser fly. :)
2. The OP may think you mean the braid that connects to the tube base
pcb, and aquadag braid to chassis is prone to coming disocnnected in
some set designs, so again this may fail at times.
3. Finally a single zap does not discharge the CRT, it typically takes
3 goes.
4. And lastly, reservoir caps must be discharged too. They are a good
deal more dangerous than CRT EHT, which is usualy not fatal and is more
or less insulated. Reservoirs OTOH are kill capable, and conductive
paths route their energy to who knows where on the board. And typically
a repair will involve handling the main board - often with both hands,
which is where the danger comes in. A cap full of 330v across the 2
hands is not something to volunteer for.

Maybe the OP should read up on Darwin Awards.


NT


It may not be "safe" but I've been doing it that way for 15 years and
never had a problem with it. Screwdriver with a wire wrapped around it
connected to the dag strap. Most of the other caps discharge themselves
but I stick a screwdriver across the big ones just to make sure.
 
H

Homer J Simpson

Jan 1, 1970
0
Or just jump in and start working on things like I did, with the internet,
who needs to waste 5 years taking a course?

What waste? I put myself through college working at my trades - no student
loans needed.

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H

Homer J Simpson

Jan 1, 1970
0
This is not safe.

Maybe the OP should read up on Darwin Awards.

The very old TV sets had nasty AC powered EHT systems that could kill. The
only way the flyback can kill is if you are holding a gun in your mouth with
one hand while you play with the TV with the other.


--
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+ Required crap appended to avoid restrictions imposed by brain +
+ damaged idiots.
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+ Server Response: '441 Posting Failed (Rejected by POST filter)', +
+ Port: 119, Secure(SSL): No, Server Error: 441,
+
+ Error Number: 0x800CCCA9
+
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The very old TV sets had nasty AC powered EHT systems that could kill.

1930s, yes. What are the odds of the OP's set being that old though?
The era of mirror-top sets and red EHT current limiting bulbs.

The
only way the flyback can kill is if you are holding a gun in your mouth with
one hand while you play with the TV with the other.

or the shock resulted in breaking the tube. Or in a recoiling hand
coming into contact with a charged reservoir cap. Or a live chassis on
an older set. Or the person had a weak heart and didnt know it. Etc.
Theres no point being silly about these things when it takes 30 seconds
to discharge EHT.


NT
 
M

Meat Plow

Jan 1, 1970
0
1930s, yes. What are the odds of the OP's set being that old though? The
era of mirror-top sets and red EHT current limiting bulbs.



or the shock resulted in breaking the tube. Or in a recoiling hand coming
into contact with a charged reservoir cap. Or a live chassis on an older
set. Or the person had a weak heart and didnt know it. Etc. Theres no
point being silly about these things when it takes 30 seconds to discharge
EHT.

Some of those old Muntz tv sets were killers.
 
H

Homer J Simpson

Jan 1, 1970
0
or the shock resulted in breaking the tube. Or in a recoiling hand
coming into contact with a charged reservoir cap. Or a live chassis on
an older set. Or the person had a weak heart and didnt know it. Etc.
Theres no point being silly about these things when it takes 30 seconds
to discharge EHT.

Indubitably, but a TV doesn't scare me a tiny bit in comparison with a
microwave -- or an 11 kV street line.


--
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+ Required crap appended to avoid restrictions imposed by brain +
+ damaged idiots.
+
+ Server Response: '441 Posting Failed (Rejected by POST filter)', +
+ Port: 119, Secure(SSL): No, Server Error: 441,
+
+ Error Number: 0x800CCCA9
+
++++++++++++++++++++++++++++++++++++++++++++++++++++
 
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