I understand at one time you couldn't take apart a TV set because
supposedly it held a charge and could kill you. It may be true, or
not, I don't know.

Now I have a microwave that went FUBAR. First the LCD didn't work
correctly. You couldn't read anything. Then it would start and stop
for no reason. Finally, the thing blew out "electrical fire" inside
the microwave. Now it will no longer heat food.

So, since it is bad, I wanted to let my kids disassemble it for
education purposes. Do I need to wait for the unit to discharge
before allowing them to mess with it? It has be unplugged for around
2 weeks.

Thanks
B
M




__________________________________________________ _______________________
The difference between a truth and a lie is:
1) Do you believe it?
2) Did you get caught?
3) Can you convince others of your conviction.
-MM
How I lost the day.

Take the door off. Cut the cord and throw it away. Microwaves excite
molecules to boil water. Your kids are made of both.

Brett Miler wrote:
I understand at one time you couldn't take apart a TV set because
supposedly it held a charge and could kill you. It may be true, or
not, I don't know.

Now I have a microwave that went FUBAR. First the LCD didn't work
correctly. You couldn't read anything. Then it would start and stop
for no reason. Finally, the thing blew out "electrical fire" inside
the microwave. Now it will no longer heat food.

So, since it is bad, I wanted to let my kids disassemble it for
education purposes. Do I need to wait for the unit to discharge
before allowing them to mess with it? It has be unplugged for around
2 weeks.

Thanks
B
M


Normally I would say it should be drained after a couple of hours, BUT
your is not working as expected. Therefore all bets are off. Those
capacitors could hold a charge for a very long time. While I suspect it is
now safe, I would not want to turn a kid loose on it without KNOWING it was
safe. It would appear you feel the same way. My recommendation is that
unless you can locate and drain each power capacitor (shop manual would be
nice to have) I would give up on the plan.

--
Joseph Meehan

Dia duit

"Joseph Meehan" wrote in message
...
Brett Miler wrote:
I understand at one time you couldn't take apart a TV set because
supposedly it held a charge and could kill you. It may be true, or
not, I don't know.

Now I have a microwave that went FUBAR. First the LCD didn't work
correctly. You couldn't read anything. Then it would start and stop
for no reason. Finally, the thing blew out "electrical fire" inside
the microwave. Now it will no longer heat food.

So, since it is bad, I wanted to let my kids disassemble it for
education purposes. Do I need to wait for the unit to discharge
before allowing them to mess with it? It has be unplugged for around
2 weeks.

Thanks
B
M


Normally I would say it should be drained after a couple of hours, BUT
your is not working as expected. Therefore all bets are off. Those
capacitors could hold a charge for a very long time. While I suspect it
is now safe, I would not want to turn a kid loose on it without KNOWING it
was safe. It would appear you feel the same way. My recommendation is
that unless you can locate and drain each power capacitor (shop manual
would be nice to have) I would give up on the plan.

--
Joseph Meehan

Dia duit
There's only one big, high voltage capacitor in there, but..... There's lots
of really sharp edges on these cheaply made cabinets. Into the metal bin
with it.

According to Brett Miler :
I understand at one time you couldn't take apart a TV set because
supposedly it held a charge and could kill you. It may be true, or
not, I don't know.

Now I have a microwave that went FUBAR. First the LCD didn't work
correctly. You couldn't read anything. Then it would start and stop
for no reason. Finally, the thing blew out "electrical fire" inside
the microwave. Now it will no longer heat food.

So, since it is bad, I wanted to let my kids disassemble it for
education purposes. Do I need to wait for the unit to discharge
before allowing them to mess with it? It has be unplugged for around
2 weeks.

TV set HT voltages are quite high (up to 25Kv or more), and it can often
be "stored" (capacitively) in the picture tube for quite a while - months
or longer. It's quite painful to be hit by it, the risk from it is more
a matter of what you do when you get hit. I remember (but only vaguely)
jumping 9 feet straight up in a basement that had a 8' ceiling. A friend
tried to discharge one once with a screwdriver, and miscued as to what he
touched first. The screwdriver embedded itself in the door frame behind
him (narrowly missing someone...).

Discharging them ain't all that difficult, but...

Microwave HT voltages aren't quite as nasty (~4Kv) and _should_ discharge
within a few minutes.

You might find this of use:

http://www.everist.org/special/mw_oven/
--
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.

Brett Miler wrote:
I understand at one time you couldn't take apart a TV set because
supposedly it held a charge and could kill you. It may be true, or
not, I don't know.

Now I have a microwave that went FUBAR. First the LCD didn't work
correctly. You couldn't read anything. Then it would start and stop
for no reason. Finally, the thing blew out "electrical fire" inside
the microwave. Now it will no longer heat food.

So, since it is bad, I wanted to let my kids disassemble it for
education purposes. Do I need to wait for the unit to discharge
before allowing them to mess with it? It has be unplugged for around
2 weeks.

Thanks
B
M




__________________________________________________ _______________________
The difference between a truth and a lie is:
1) Do you believe it?
2) Did you get caught?
3) Can you convince others of your conviction.
-MM
How I lost the day.


----------------------------------------------------------------------------------------------------
Its my understanding a Microware contains a cathode-ray tube which is
radio active. There fore something kids should not play with.

If it is junk then see that it is JUNKED for the safety of your
children.

MICROWAVES ARE NOT PLAY TOYS PERIOD!-!-!-!

On Tue, 07 Mar 2006 02:18:17 -0500, Brett Miler
wrote:

I understand at one time you couldn't take apart a TV set because
supposedly it held a charge and could kill you. It may be true, or
not, I don't know.

Now I have a microwave that went FUBAR. First the LCD didn't work
correctly. You couldn't read anything. Then it would start and stop
for no reason. Finally, the thing blew out "electrical fire" inside
the microwave. Now it will no longer heat food.

So, since it is bad, I wanted to let my kids disassemble it for
education purposes. Do I need to wait for the unit to discharge
before allowing them to mess with it? It has be unplugged for around
2 weeks.

Thanks
B

Cut the cord off, and take the capacitor out yourself.
THEN let them dissemble it.

Goedjn wrote:

On Tue, 07 Mar 2006 02:18:17 -0500, Brett Miler
wrote:


I understand at one time you couldn't take apart a TV set because
supposedly it held a charge and could kill you. It may be true, or
not, I don't know.

Now I have a microwave that went FUBAR. First the LCD didn't work
correctly. You couldn't read anything. Then it would start and stop
for no reason. Finally, the thing blew out "electrical fire" inside
the microwave. Now it will no longer heat food.

So, since it is bad, I wanted to let my kids disassemble it for
education purposes. Do I need to wait for the unit to discharge
before allowing them to mess with it? It has be unplugged for around
2 weeks.

Thanks
B


Cut the cord off, and take the capacitor out yourself.
THEN let them dissemble it.



Good idea...

And, for those here who've never learned about "dielectric adsorbtion"
in capacitors (or been zapped by it.) read on:

http://www.faradnet.com/glossary/d_gloss.htm#da

Jeff

--
Jeffry Wisnia

(W1BSV + Brass Rat '57 EE)

"Truth exists; only falsehood has to be invented."

Brett Miler wrote:

I understand at one time you couldn't take apart a TV set because
supposedly it held a charge and could kill you. It may be true, or
not, I don't know.

Now I have a microwave that went FUBAR. First the LCD didn't work
correctly. You couldn't read anything. Then it would start and stop
for no reason. Finally, the thing blew out "electrical fire" inside
the microwave. Now it will no longer heat food.

So, since it is bad, I wanted to let my kids disassemble it for
education purposes. Do I need to wait for the unit to discharge
before allowing them to mess with it? It has be unplugged for around
2 weeks.

It's probably safe by now, but don't take chances. There's a large high
voltage capacitor, approximately 2" x 3" x 1", that can retain a few
thousand volts indefinitely if its bleeder resistor fails, and bleeder
resistors do fail. It must be discharged by unplugging the AC cord and
then shorting the capacitor's 2 terminals together with a
plastic-handled screwdriver (merely wrapping a metal screwdriver handle
with electrical tape is NOT adequate). But this may not be possible
because of the physical placement of the terminals, in which case each
terminal should be individually shorted to the oven's chassis. Do this
by wrapping some bare wire around a screwdriver shaft and connecting
the other end of the wire securely to bare metal inside the chassis
(you may have to loosen a nut or bolt to insert the wire under it and
then tighten for a good connection). Then and only then touch the
screwdriver's metal tip to each capacitor terminal.

If the high voltage capacitor isn't discharged, it can be a much worse
hazard than a picture tube, despite the much lower voltage, because at
least the picture tube won't put out a lethal level of current, as a
microwave oven capacitor can.

There is no radiation from the magnatron tube when the power is turned
off.

Do NOT let your children play with the large transformer, which puts
out 1,000 volts when plugged into 120VAC. So after discharging the
oven's high voltage capacitor, clip all the transformer's wires flush
so it can't be used. Some ovens may instead have a high-frequency
power supply with a much smaller transformer on a circuit board. I
suggest removing that as well and destroying it.

The magnatron tube has a pair of large ring magnets that most people
want. They're epoxied to the metal body, but at least one magnet may
have cracked by now.

wrote:
...
Its my understanding a Microware contains a cathode-ray tube which is
radio active. There fore something kids should not play with.

If it is junk then see that it is JUNKED for the safety of your
children.

MICROWAVES ARE NOT PLAY TOYS PERIOD!-!-!-!

Nothing radioactive in there. No cathode-ray tubes there either, but
you do have a big one on most TV sets.

--
Joseph Meehan

Dia duit

On 7 Mar 2006 07:11:24 -0800, wrote:


Brett Miler wrote:
I understand at one time you couldn't take apart a TV set because
supposedly it held a charge and could kill you. It may be true, or
not, I don't know.

Now I have a microwave that went FUBAR. First the LCD didn't work
correctly. You couldn't read anything. Then it would start and stop
for no reason. Finally, the thing blew out "electrical fire" inside
the microwave. Now it will no longer heat food.

So, since it is bad, I wanted to let my kids disassemble it for
education purposes. Do I need to wait for the unit to discharge
before allowing them to mess with it? It has be unplugged for around
2 weeks.

Thanks
B
M




__________________________________________________ _______________________
The difference between a truth and a lie is:
1) Do you believe it?
2) Did you get caught?
3) Can you convince others of your conviction.
-MM
How I lost the day.


----------------------------------------------------------------------------------------------------
Its my understanding a Microware contains a cathode-ray tube

No, it's a magnetron.

which is
radio active.

They're not.

Magnetrons emit electromagnetic (EM) radiation, something very
different from nuclear radiation, and not present unless the device is
operating. Mainly what you have to worry about is high voltage.

There fore something kids should not play with.

If it is junk then see that it is JUNKED for the safety of your
children.

MICROWAVES ARE NOT PLAY TOYS PERIOD!-!-!-!
--
Mark Lloyd
http://notstupid.laughingsquid.com

"Democracy is two wolves and a lamb voting on what
to have for lunch. Liberty is a well armed lamb
contesting the vote." - Benjamin Franklin

Goedjn wrote:
On Tue, 07 Mar 2006 02:18:17 -0500, Brett Miler
wrote:

I understand at one time you couldn't take apart a TV set because
supposedly it held a charge and could kill you. It may be true, or
not, I don't know.

Now I have a microwave that went FUBAR. First the LCD didn't work
correctly. You couldn't read anything. Then it would start and stop
for no reason. Finally, the thing blew out "electrical fire" inside
the microwave. Now it will no longer heat food.

So, since it is bad, I wanted to let my kids disassemble it for
education purposes. Do I need to wait for the unit to discharge
before allowing them to mess with it? It has be unplugged for around
2 weeks.

Thanks
B

Cut the cord off, and take the capacitor out yourself.
THEN let them dissemble it.

Or chuck it in a farm pond for a few days and then let the kids fish it
out to play with.

On Tue, 7 Mar 2006 08:00:56 -0500, "Bob"
wrote:


"Joseph Meehan" wrote in message
.. .
Brett Miler wrote:
I understand at one time you couldn't take apart a TV set because
supposedly it held a charge and could kill you. It may be true, or
not, I don't know.

Now I have a microwave that went FUBAR. First the LCD didn't work
correctly. You couldn't read anything. Then it would start and stop
for no reason. Finally, the thing blew out "electrical fire" inside
the microwave. Now it will no longer heat food.

So, since it is bad, I wanted to let my kids disassemble it for
education purposes. Do I need to wait for the unit to discharge
before allowing them to mess with it? It has be unplugged for around
2 weeks.

Thanks
B
M


Normally I would say it should be drained after a couple of hours, BUT
your is not working as expected. Therefore all bets are off. Those
capacitors could hold a charge for a very long time. While I suspect it
is now safe, I would not want to turn a kid loose on it without KNOWING it
was safe. It would appear you feel the same way. My recommendation is
that unless you can locate and drain each power capacitor (shop manual
would be nice to have) I would give up on the plan.

--
Joseph Meehan

Dia duit
There's only one big, high voltage capacitor in there, but..... There's lots
of really sharp edges on these cheaply made cabinets. Into the metal bin
with it.


Ohhhh, lots of sharp metal.... scarey !!!!
Lets protect our kids from everything so they end up with no brains at
all, and go out on the streets with drugs and guns because their
parents would not let them live normal lives, and be cuious and
creative, or should I say "be kids".

That reminds me of a guy who would not let his kids ride the shetland
pony he bought as their pet, because they might get hurt. So one of
the kids got hurt trying to ride one of their cows. When the father
was scolding the kid after the accident, the kid said "you said I
could not ride pony, so I rode the cow".

To the OP. if you are concerned, take off the MW cover and short a
screwdriver across the large capacitor. Cut off the cord, replace the
cover and give it to the kids.

I suspect the sparks you saw WAS that capacitor. It fried....
Which leads to one other thing. If gobs of nasty stuff came out of
that capacitor, them you might NOT want to let the kids touch it.
That could be toxic and far more dangerous than sharp metal. Why not
let the kids watch you open the thing, short the cap, etc. Teach them
something in he process....

On 7 Mar 2006 07:11:24 -0800, wrote:


Brett Miler wrote:
I understand at one time you couldn't take apart a TV set because
supposedly it held a charge and could kill you. It may be true, or
not, I don't know.

Now I have a microwave that went FUBAR. First the LCD didn't work
correctly. You couldn't read anything. Then it would start and stop
for no reason. Finally, the thing blew out "electrical fire" inside
the microwave. Now it will no longer heat food.

So, since it is bad, I wanted to let my kids disassemble it for
education purposes. Do I need to wait for the unit to discharge
before allowing them to mess with it? It has be unplugged for around
2 weeks.

Thanks
B
M




__________________________________________________ _______________________
The difference between a truth and a lie is:
1) Do you believe it?
2) Did you get caught?
3) Can you convince others of your conviction.
-MM
How I lost the day.


----------------------------------------------------------------------------------------------------
Its my understanding a Microware contains a cathode-ray tube which is
radio active. There fore something kids should not play with.

If it is junk then see that it is JUNKED for the safety of your
children.

MICROWAVES ARE NOT PLAY TOYS PERIOD!-!-!-!

Damn....
You just Flunked electronics class !!!!
None of what you said is correct.

On Tue, 07 Mar 2006 18:43:56 -0600, wrote:

On 7 Mar 2006 10:40:50 -0800, wrote:


Brett Miler wrote:

I understand at one time you couldn't take apart a TV set because
supposedly it held a charge and could kill you. It may be true, or
not, I don't know.

Now I have a microwave that went FUBAR. First the LCD didn't work
correctly. You couldn't read anything. Then it would start and stop
for no reason. Finally, the thing blew out "electrical fire" inside
the microwave. Now it will no longer heat food.

So, since it is bad, I wanted to let my kids disassemble it for
education purposes. Do I need to wait for the unit to discharge
before allowing them to mess with it? It has be unplugged for around
2 weeks.

It's probably safe by now, but don't take chances. There's a large high
voltage capacitor, approximately 2" x 3" x 1", that can retain a few
thousand volts indefinitely if its bleeder resistor fails, and bleeder
resistors do fail. It must be discharged by unplugging the AC cord and
then shorting the capacitor's 2 terminals together with a
plastic-handled screwdriver (merely wrapping a metal screwdriver handle
with electrical tape is NOT adequate). But this may not be possible
because of the physical placement of the terminals, in which case each
terminal should be individually shorted to the oven's chassis. Do this
by wrapping some bare wire around a screwdriver shaft and connecting
the other end of the wire securely to bare metal inside the chassis
(you may have to loosen a nut or bolt to insert the wire under it and
then tighten for a good connection). Then and only then touch the
screwdriver's metal tip to each capacitor terminal.

If the high voltage capacitor isn't discharged, it can be a much worse
hazard than a picture tube, despite the much lower voltage, because at
least the picture tube won't put out a lethal level of current, as a
microwave oven capacitor can.

There is no radiation from the magnatron tube when the power is turned
off.

Do NOT let your children play with the large transformer, which puts
out 1,000 volts when plugged into 120VAC. So after discharging the
oven's high voltage capacitor, clip all the transformer's wires flush
so it can't be used. Some ovens may instead have a high-frequency
power supply with a much smaller transformer on a circuit board. I
suggest removing that as well and destroying it.

The magnatron tube has a pair of large ring magnets that most people
want. They're epoxied to the metal body, but at least one magnet may
have cracked by now.

Just cut off the cord for heavens sake.... The thing already blew
sparks and smoke and there is no reason the kids should have the
opportunity to get shocked or start a fire. No cord, no danger...
Besides that, MW cords are excellent to reuse. In fact I made a 6
foot heavy duty extension cord out of one of them for my gas range.
The cord on the range was too short to reach the outlet, and all I
could find to buy was an expensive 14-2 +g extension cord that was 15
feet (too long). Or one of those super heavy duty air cond. cords
(also expensive). The MW cord and a $3 female plug solved the
problem.

It is hard to get short, thick extension cords.
--
Mark Lloyd
http://notstupid.laughingsquid.com

"Democracy is two wolves and a lamb voting on what
to have for lunch. Liberty is a well armed lamb
contesting the vote." - Benjamin Franklin

wrote:
On 7 Mar 2006 10:40:50 -0800, wrote:


Brett Miler wrote:


I understand at one time you couldn't take apart a TV set because
supposedly it held a charge and could kill you. It may be true, or
not, I don't know.

Now I have a microwave that went FUBAR. First the LCD didn't work
correctly. You couldn't read anything. Then it would start and stop
for no reason. Finally, the thing blew out "electrical fire" inside
the microwave. Now it will no longer heat food.

So, since it is bad, I wanted to let my kids disassemble it for
education purposes. Do I need to wait for the unit to discharge
before allowing them to mess with it? It has be unplugged for around
2 weeks.

It's probably safe by now, but don't take chances. There's a large high
voltage capacitor, approximately 2" x 3" x 1", that can retain a few
thousand volts indefinitely if its bleeder resistor fails, and bleeder
resistors do fail. It must be discharged by unplugging the AC cord and
then shorting the capacitor's 2 terminals together with a
plastic-handled screwdriver (merely wrapping a metal screwdriver handle
with electrical tape is NOT adequate). But this may not be possible
because of the physical placement of the terminals, in which case each
terminal should be individually shorted to the oven's chassis. Do this
by wrapping some bare wire around a screwdriver shaft and connecting
the other end of the wire securely to bare metal inside the chassis
(you may have to loosen a nut or bolt to insert the wire under it and
then tighten for a good connection). Then and only then touch the
screwdriver's metal tip to each capacitor terminal.

If the high voltage capacitor isn't discharged, it can be a much worse
hazard than a picture tube, despite the much lower voltage, because at
least the picture tube won't put out a lethal level of current, as a
microwave oven capacitor can.

There is no radiation from the magnatron tube when the power is turned
off.

Do NOT let your children play with the large transformer, which puts
out 1,000 volts when plugged into 120VAC. So after discharging the
oven's high voltage capacitor, clip all the transformer's wires flush
so it can't be used. Some ovens may instead have a high-frequency
power supply with a much smaller transformer on a circuit board. I
suggest removing that as well and destroying it.

The magnatron tube has a pair of large ring magnets that most people
want. They're epoxied to the metal body, but at least one magnet may
have cracked by now.


Just cut off the cord for heavens sake.... The thing already blew
sparks and smoke and there is no reason the kids should have the
opportunity to get shocked or start a fire. No cord, no danger...
Besides that, MW cords are excellent to reuse. In fact I made a 6
foot heavy duty extension cord out of one of them for my gas range.
The cord on the range was too short to reach the outlet, and all I
could find to buy was an expensive 14-2 +g extension cord that was 15
feet (too long). Or one of those super heavy duty air cond. cords
(also expensive). The MW cord and a $3 female plug solved the
problem.


Uhmmm, I suggest that you look at that MW cord you
cut off and check what it says is the size of the
wire. Mine says it is 16 gauge, lots of
insulation, not much copper.

You are doing something wrong or living in the
wrong place if all you can find is an expensive
14-2 extension cord. I have an extension with a
multiple outlet bar is 14-3, 6 foot long, and cost
$3. You need to check Walmart. Sure you can
spend $6 or even $12 if it has a surge protector
but you don't need to.

Mark Lloyd wrote:
On Tue, 07 Mar 2006 18:43:56 -0600, wrote:


On 7 Mar 2006 10:40:50 -0800, wrote:


Brett Miler wrote:


I understand at one time you couldn't take apart a TV set because
supposedly it held a charge and could kill you. It may be true, or
not, I don't know.

Now I have a microwave that went FUBAR. First the LCD didn't work
correctly. You couldn't read anything. Then it would start and stop
for no reason. Finally, the thing blew out "electrical fire" inside
the microwave. Now it will no longer heat food.

So, since it is bad, I wanted to let my kids disassemble it for
education purposes. Do I need to wait for the unit to discharge
before allowing them to mess with it? It has be unplugged for around
2 weeks.

It's probably safe by now, but don't take chances. There's a large high
voltage capacitor, approximately 2" x 3" x 1", that can retain a few
thousand volts indefinitely if its bleeder resistor fails, and bleeder
resistors do fail. It must be discharged by unplugging the AC cord and
then shorting the capacitor's 2 terminals together with a
plastic-handled screwdriver (merely wrapping a metal screwdriver handle
with electrical tape is NOT adequate). But this may not be possible
because of the physical placement of the terminals, in which case each
terminal should be individually shorted to the oven's chassis. Do this
by wrapping some bare wire around a screwdriver shaft and connecting
the other end of the wire securely to bare metal inside the chassis
(you may have to loosen a nut or bolt to insert the wire under it and
then tighten for a good connection). Then and only then touch the
screwdriver's metal tip to each capacitor terminal.

If the high voltage capacitor isn't discharged, it can be a much worse
hazard than a picture tube, despite the much lower voltage, because at
least the picture tube won't put out a lethal level of current, as a
microwave oven capacitor can.

There is no radiation from the magnatron tube when the power is turned
off.

Do NOT let your children play with the large transformer, which puts
out 1,000 volts when plugged into 120VAC. So after discharging the
oven's high voltage capacitor, clip all the transformer's wires flush
so it can't be used. Some ovens may instead have a high-frequency
power supply with a much smaller transformer on a circuit board. I
suggest removing that as well and destroying it.

The magnatron tube has a pair of large ring magnets that most people
want. They're epoxied to the metal body, but at least one magnet may
have cracked by now.

Just cut off the cord for heavens sake.... The thing already blew
sparks and smoke and there is no reason the kids should have the
opportunity to get shocked or start a fire. No cord, no danger...
Besides that, MW cords are excellent to reuse. In fact I made a 6
foot heavy duty extension cord out of one of them for my gas range.
The cord on the range was too short to reach the outlet, and all I
could find to buy was an expensive 14-2 +g extension cord that was 15
feet (too long). Or one of those super heavy duty air cond. cords
(also expensive). The MW cord and a $3 female plug solved the
problem.


It is hard to get short, thick extension cords.

Sure it is, just bought a 3-foot one at Walmart
for $1.99.

Brett Miler wrote:
I understand at one time you couldn't take apart a TV set because
supposedly it held a charge and could kill you. It may be true, or
not, I don't know.

Now I have a microwave that went FUBAR. First the LCD didn't work
correctly. You couldn't read anything. Then it would start and stop
for no reason. Finally, the thing blew out "electrical fire" inside
the microwave. Now it will no longer heat food.

So, since it is bad, I wanted to let my kids disassemble it for
education purposes. Do I need to wait for the unit to discharge
before allowing them to mess with it? It has be unplugged for around
2 weeks.

Give it to 'em now. Don't you want your kids to have the same opportunites
you had?

On Wed, 08 Mar 2006 20:37:13 GMT, "George E. Cawthon"
wrote:

Mark Lloyd wrote:
On Tue, 07 Mar 2006 18:43:56 -0600, wrote:


On 7 Mar 2006 10:40:50 -0800, wrote:


Brett Miler wrote:


I understand at one time you couldn't take apart a TV set because
supposedly it held a charge and could kill you. It may be true, or
not, I don't know.

Now I have a microwave that went FUBAR. First the LCD didn't work
correctly. You couldn't read anything. Then it would start and stop
for no reason. Finally, the thing blew out "electrical fire" inside
the microwave. Now it will no longer heat food.

So, since it is bad, I wanted to let my kids disassemble it for
education purposes. Do I need to wait for the unit to discharge
before allowing them to mess with it? It has be unplugged for around
2 weeks.

It's probably safe by now, but don't take chances. There's a large high
voltage capacitor, approximately 2" x 3" x 1", that can retain a few
thousand volts indefinitely if its bleeder resistor fails, and bleeder
resistors do fail. It must be discharged by unplugging the AC cord and
then shorting the capacitor's 2 terminals together with a
plastic-handled screwdriver (merely wrapping a metal screwdriver handle
with electrical tape is NOT adequate). But this may not be possible
because of the physical placement of the terminals, in which case each
terminal should be individually shorted to the oven's chassis. Do this
by wrapping some bare wire around a screwdriver shaft and connecting
the other end of the wire securely to bare metal inside the chassis
(you may have to loosen a nut or bolt to insert the wire under it and
then tighten for a good connection). Then and only then touch the
screwdriver's metal tip to each capacitor terminal.

If the high voltage capacitor isn't discharged, it can be a much worse
hazard than a picture tube, despite the much lower voltage, because at
least the picture tube won't put out a lethal level of current, as a
microwave oven capacitor can.

There is no radiation from the magnatron tube when the power is turned
off.

Do NOT let your children play with the large transformer, which puts
out 1,000 volts when plugged into 120VAC. So after discharging the
oven's high voltage capacitor, clip all the transformer's wires flush
so it can't be used. Some ovens may instead have a high-frequency
power supply with a much smaller transformer on a circuit board. I
suggest removing that as well and destroying it.

The magnatron tube has a pair of large ring magnets that most people
want. They're epoxied to the metal body, but at least one magnet may
have cracked by now.

Just cut off the cord for heavens sake.... The thing already blew
sparks and smoke and there is no reason the kids should have the
opportunity to get shocked or start a fire. No cord, no danger...
Besides that, MW cords are excellent to reuse. In fact I made a 6
foot heavy duty extension cord out of one of them for my gas range.
The cord on the range was too short to reach the outlet, and all I
could find to buy was an expensive 14-2 +g extension cord that was 15
feet (too long). Or one of those super heavy duty air cond. cords
(also expensive). The MW cord and a $3 female plug solved the
problem.


It is hard to get short, thick extension cords.

Sure it is, just bought a 3-foot one at Walmart
for $1.99.

I guess that's changed. They didn't have any when I looked.
--
Mark Lloyd
http://notstupid.laughingsquid.com

"Democracy is two wolves and a lamb voting on what
to have for lunch. Liberty is a well armed lamb
contesting the vote." - Benjamin Franklin

HeyBub wrote:

Brett Miler wrote:

Now I have a microwave that went FUBAR. First the LCD didn't work
correctly. You couldn't read anything. Then it would start and stop
for no reason. Finally, the thing blew out "electrical fire" inside
the microwave. Now it will no longer heat food.


Give it to 'em now. Don't you want your kids to have the same opportunites
you had?



lots of hardware, bolts, nuts, washers, little switches,
fan, little motor. Give the big transformer to your local
ham radio operator. All the magnetrons I've removed were
easily disassembled by removing 4 self-tap screws. Slide
off the frame and heat sink fins to remove the magnets. Pry
open the (filament filter) can to get the rf coils (if you
can use such things). Metal reclaim the remainder. Most
have safety glass in the door if you can use that size.

I agree, we need to let our kids learn by doing! I would
warn the kids that those magnets have a real affinity for
each other, and will really hurt with a small finger between
them!

-larry / dallas

You know I graduated with a degree in Electrical Engineering and had
been working for a few yeras. Nobody ever felt the need to tell me
about this TV discharge thing. I discharged a 'dead' TV the hard way...

Brett Miler wrote:
I understand at one time you couldn't take apart a TV set because
supposedly it held a charge and could kill you. It may be true, or
not, I don't know.

Now I have a microwave that went FUBAR. First the LCD didn't work
correctly. You couldn't read anything. Then it would start and stop
for no reason. Finally, the thing blew out "electrical fire" inside
the microwave. Now it will no longer heat food.

So, since it is bad, I wanted to let my kids disassemble it for
education purposes. Do I need to wait for the unit to discharge
before allowing them to mess with it? It has be unplugged for around
2 weeks.

Thanks
B
M




__________________________________________________ _______________________
The difference between a truth and a lie is:
1) Do you believe it?
2) Did you get caught?
3) Can you convince others of your conviction.
-MM
How I lost the day.


--
Thank you,



"Then said I, Wisdom [is] better than strength: nevertheless the poor
man's wisdom [is] despised, and his words are not heard." Ecclesiastes 9:16

mm wrote:
On Wed, 08 Mar 2006 23:48:06 -0500, dnoyeB
wrote:


You know I graduated with a degree in Electrical Engineering and had
been working for a few yeras. Nobody ever felt the need to tell me
about this TV discharge thing. I discharged a 'dead' TV the hard way...


Engineering is about designing them, or building them.

You needed to take a course in repair!

I never got shocked from a picture tube, but once, when I was being
careful, I must have made a mistake and gotten 2KV, because I jumped
back 10 feet with a dislocated shoulder. It hadn't been out in 8
years, and I thought it was healed (after 10 previous dislocations.)
Witihin 3 months it was coming out 4 times in one week, and I had to
have surgery. Good doctor. No problems since.

Yea my shoulder has been flaky since an injury long ago. I ended up
having surgery. I think its the Tae Kwon Do that has strengthen the
joint the most though. It rarely comes out nowadays.

--
Thank you,



"Then said I, Wisdom [is] better than strength: nevertheless the poor
man's wisdom [is] despised, and his words are not heard." Ecclesiastes 9:16

On Thu, 09 Mar 2006 09:32:34 -0500, mm
wrote:

On Thu, 09 Mar 2006 08:51:54 -0500, dnoyeB
wrote:


I never got shocked from a picture tube, but once, when I was being
careful, I must have made a mistake and gotten 2KV, because I jumped
back 10 feet with a dislocated shoulder. It hadn't been out in 8
years, and I thought it was healed (after 10 previous dislocations.)
Witihin 3 months it was coming out 4 times in one week, and I had to
have surgery. Good doctor. No problems since.

Yea my shoulder has been flaky since an injury long ago. I ended up
having surgery. I think its the Tae Kwon Do that has strengthen the
joint the most though. It rarely comes out nowadays.

Yeah, I had a hard work summer job that helped my shoulder a lot. But
it wasn't enough to resist 2000 volts.

--
Yeah, ummmhu. Shore nuff. If only I had knowed I only had to wait
PLEASE INSERT ANSWER HERE then I could have told that young fellow how
long he had to wait. PRobalby long enought to hear bout my shoulder.

Yeah, if he only know that you had to wait INSERT TIME
HERE...................


ughhhhhh!