This TV (Electrohome/Mitsubishi Model 69CK03, Chassis UM2-C-10R) would
power up and immediately blow the fuse on the "cold" side of the circuit
board. On the "hot" side (power supply) after changing the bridge
rectifier, everything checks normal. I get 125 volts using a 100W light
bulb at the (removed) collecter of the HOT. I changed the flyback. The
fuse no longer blows, but the TV goes into shutdown. I removed the CRT
circuit board, then pressed the power button and got zapped by the high
voltage. No longer taking a chance with my finger on the power button, I
used a remote to turn on the TV. There's a cap between the two 120V
line inputs (.01mfd 250V). A piece of plastic surrounds part of the
circuit board. When powering up the TV, arcing occurs from one end of
the cap to the plastic. I checked the plastic. There's nothing under it.
This is arcing from one of the line inputs. I removed the anode from
the TV and measured the high voltage. My meter went up to 40K. I
disconnected the TV before it got any higher. No arcing occured with the
anode disconnected.
I think that the high voltage is crossing over from the "cold" side to
the "hot" side of the board. Or from the anode to the ground straps on
the TV tube, to all grounds on the board. Any comments?

Arnold stewart wrote:

This TV (Electrohome/Mitsubishi Model 69CK03, Chassis UM2-C-10R) would
power up and immediately blow the fuse on the "cold" side of the circuit
board. On the "hot" side (power supply) after changing the bridge
rectifier, everything checks normal. I get 125 volts using a 100W light
bulb at the (removed) collecter of the HOT. I changed the flyback. The
fuse no longer blows, but the TV goes into shutdown. I removed the CRT
circuit board, then pressed the power button and got zapped by the high
voltage. No longer taking a chance with my finger on the power button, I
used a remote to turn on the TV. There's a cap between the two 120V
line inputs (.01mfd 250V). A piece of plastic surrounds part of the
circuit board. When powering up the TV, arcing occurs from one end of
the cap to the plastic. I checked the plastic. There's nothing under it.
This is arcing from one of the line inputs. I removed the anode from
the TV and measured the high voltage. My meter went up to 40K. I
disconnected the TV before it got any higher. No arcing occured with the
anode disconnected.
I think that the high voltage is crossing over from the "cold" side to
the "hot" side of the board. Or from the anode to the ground straps on
the TV tube, to all grounds on the board. Any comments?


Yes, indeed. With all due respect, stop! (while the
choice is still yours).

Take care.

Ken

I'll second that advice. I am not a professional serviceman, but have
repaired my own TVs. I did study a technical book on the operation and
troubleshooting of color TVs. On my original color TV I had this problem of
what appeared to be arcing, with the raster collapsing and recovering
spasmodically. Then there'd be a flash, and most of the transistors in the
TV would be blown. I subsequently read in a serviceman's magazine about a
capacitor in the EHT circuit which, when defective, can cause a massive
increase in the EHT voltage. I replaced that capacitor and the problem was
gone for good.

I welcome the professional servicemen here to correct me, as I am speaking
from a semi-ignorant level. The one thing I will say positively, is that the
EHT on a color TV is most DANGEROUS, much more so than on a B/W, and can
easily kill you, even without touching any components. As well as that there
may be some radiation. Unless you are very familliar with color TVs you
should refer the problem to a professional serviceman.

Henry
Australia

"Ken Weitzel" wrote in message
news:jRPoc.465033$Ig.425208@pd7tw2no...


Arnold stewart wrote:

This TV (Electrohome/Mitsubishi Model 69CK03, Chassis UM2-C-10R) would
power up and immediately blow the fuse on the "cold" side of the circuit
board. On the "hot" side (power supply) after changing the bridge
rectifier, everything checks normal. I get 125 volts using a 100W light
bulb at the (removed) collecter of the HOT. I changed the flyback. The
fuse no longer blows, but the TV goes into shutdown. I removed the CRT
circuit board, then pressed the power button and got zapped by the high
voltage. No longer taking a chance with my finger on the power button, I
used a remote to turn on the TV. There's a cap between the two 120V
line inputs (.01mfd 250V). A piece of plastic surrounds part of the
circuit board. When powering up the TV, arcing occurs from one end of
the cap to the plastic. I checked the plastic. There's nothing under it.
This is arcing from one of the line inputs. I removed the anode from
the TV and measured the high voltage. My meter went up to 40K. I
disconnected the TV before it got any higher. No arcing occured with the
anode disconnected.
I think that the high voltage is crossing over from the "cold" side to
the "hot" side of the board. Or from the anode to the ground straps on
the TV tube, to all grounds on the board. Any comments?


Yes, indeed. With all due respect, stop! (while the
choice is still yours).

Take care.

Ken

Straight On, Mate!!! Flippin Russian Roulette with 40KV!!! Have the tele
serviced by a professional service company.
"hemyd" wrote in message
. au...
I'll second that advice. I am not a professional serviceman, but have
repaired my own TVs. I did study a technical book on the operation and
troubleshooting of color TVs. On my original color TV I had this problem
of
what appeared to be arcing, with the raster collapsing and recovering
spasmodically. Then there'd be a flash, and most of the transistors in the
TV would be blown. I subsequently read in a serviceman's magazine about a
capacitor in the EHT circuit which, when defective, can cause a massive
increase in the EHT voltage. I replaced that capacitor and the problem was
gone for good.

I welcome the professional servicemen here to correct me, as I am speaking
from a semi-ignorant level. The one thing I will say positively, is that
the
EHT on a color TV is most DANGEROUS, much more so than on a B/W, and can
easily kill you, even without touching any components. As well as that
there
may be some radiation. Unless you are very familliar with color TVs you
should refer the problem to a professional serviceman.

Henry
Australia

"Ken Weitzel" wrote in message
news:jRPoc.465033$Ig.425208@pd7tw2no...


Arnold stewart wrote:

This TV (Electrohome/Mitsubishi Model 69CK03, Chassis UM2-C-10R) would
power up and immediately blow the fuse on the "cold" side of the
circuit
board. On the "hot" side (power supply) after changing the bridge
rectifier, everything checks normal. I get 125 volts using a 100W light
bulb at the (removed) collecter of the HOT. I changed the flyback. The
fuse no longer blows, but the TV goes into shutdown. I removed the CRT
circuit board, then pressed the power button and got zapped by the high
voltage. No longer taking a chance with my finger on the power button,
I
used a remote to turn on the TV. There's a cap between the two 120V
line inputs (.01mfd 250V). A piece of plastic surrounds part of the
circuit board. When powering up the TV, arcing occurs from one end of
the cap to the plastic. I checked the plastic. There's nothing under
it.
This is arcing from one of the line inputs. I removed the anode from
the TV and measured the high voltage. My meter went up to 40K. I
disconnected the TV before it got any higher. No arcing occured with
the
anode disconnected.
I think that the high voltage is crossing over from the "cold" side to
the "hot" side of the board. Or from the anode to the ground straps on
the TV tube, to all grounds on the board. Any comments?


Yes, indeed. With all due respect, stop! (while the
choice is still yours).

Take care.

Ken

I hope you are carrying a descent life insurance policy that will cover you
for negligence out of the lack of common sense!

First of all, the set does have some major problems that you are not
equipped or trained to deal with. These problems start from the power supply
through to the high voltage section.

Your procedure is futile if anything. No service man in his right mind would
follow the procedures that you are doing to troubleshoot the set.

You are dealing with very high voltages that can lethal if you were to take
a direct hit from them. The high voltage from the high voltage output of the
flyback may have a very low current, but the total power factor is very
high, especially from a discharge to a load, such as a person. A hit from
the high voltage can also cause neurological damage to the nervous system,
and other related injuries as well. It can also kill someone.

The main power supply voltage for the HOT section may be around 150 to 170
Volts, but its current is high enough to cause permanent injury or death.

After all the messing around you did, I would not dare to operate this set,
unless I was able to follow the proper procedure to make sure that the high
voltage is correct, and the safety hold down sensing is correct to protect
from X-Ray emissions. It is possible to have a set that looks like it is
working well, but may be radiating X-Rays or EMR that are beyond the
allowable standards.

I would very strongly suggest you get the set over to a service centre and
have it properly checked. They can give you an estimate, and then service
the set in a safe and reliable manner. If you did too much damage, it is
possible that the estimate may be too high to have the set being worth to
service.

This example is one where I agree with the philosophy of some of these
manufactures where they do not want to sell spare parts to non-authorized
service people. There is a fear where people can be injured trying to
service their set, and then try to sue the manufacture.

--

Greetings,

Jerry G.
=====

"Arnold stewart" wrote in message
...
This TV (Electrohome/Mitsubishi Model 69CK03, Chassis UM2-C-10R) would
power up and immediately blow the fuse on the "cold" side of the circuit
board. On the "hot" side (power supply) after changing the bridge
rectifier, everything checks normal. I get 125 volts using a 100W light
bulb at the (removed) collecter of the HOT. I changed the flyback. The
fuse no longer blows, but the TV goes into shutdown. I removed the CRT
circuit board, then pressed the power button and got zapped by the high
voltage. No longer taking a chance with my finger on the power button, I
used a remote to turn on the TV. There's a cap between the two 120V
line inputs (.01mfd 250V). A piece of plastic surrounds part of the
circuit board. When powering up the TV, arcing occurs from one end of
the cap to the plastic. I checked the plastic. There's nothing under it.
This is arcing from one of the line inputs. I removed the anode from
the TV and measured the high voltage. My meter went up to 40K. I
disconnected the TV before it got any higher. No arcing occured with the
anode disconnected.
I think that the high voltage is crossing over from the "cold" side to
the "hot" side of the board. Or from the anode to the ground straps on
the TV tube, to all grounds on the board. Any comments?

I don't think you got the point. I have been servicing TV's for over 20
years. What I was trying to get across was that this was the first time
I ever got zapped by high voltage by only touching the power button on
the circuit board, and touching nothing else. I was also sitting on a
wooden chair with my feet off the ground. How many people ever got
zapped by pushing a plastic power button? And, as mentioned before, I
had checked the power supply for excessive voltage output. I know all
the dangers of servicing TV's, but this was really unexpected, and I
wonder to how many people did this ever happen to? (I did not go into
all the servicing procedures I did in my post. Post would have been too
long)

Jerry G. wrote:
I hope you are carrying a descent life insurance policy that will cover you
for negligence out of the lack of common sense!

First of all, the set does have some major problems that you are not
equipped or trained to deal with. These problems start from the power supply
through to the high voltage section.

Your procedure is futile if anything. No service man in his right mind would
follow the procedures that you are doing to troubleshoot the set.

You are dealing with very high voltages that can lethal if you were to take
a direct hit from them. The high voltage from the high voltage output of the
flyback may have a very low current, but the total power factor is very
high, especially from a discharge to a load, such as a person. A hit from
the high voltage can also cause neurological damage to the nervous system,
and other related injuries as well. It can also kill someone.

The main power supply voltage for the HOT section may be around 150 to 170
Volts, but its current is high enough to cause permanent injury or death.

After all the messing around you did, I would not dare to operate this set,
unless I was able to follow the proper procedure to make sure that the high
voltage is correct, and the safety hold down sensing is correct to protect
from X-Ray emissions. It is possible to have a set that looks like it is
working well, but may be radiating X-Rays or EMR that are beyond the
allowable standards.

I would very strongly suggest you get the set over to a service centre and
have it properly checked. They can give you an estimate, and then service
the set in a safe and reliable manner. If you did too much damage, it is
possible that the estimate may be too high to have the set being worth to
service.

This example is one where I agree with the philosophy of some of these
manufactures where they do not want to sell spare parts to non-authorized
service people. There is a fear where people can be injured trying to
service their set, and then try to sue the manufacture.

I ever got zapped by high voltage by only touching the power button on
the circuit board, and touching nothing else. I was also sitting on a
wooden chair with my feet off the ground. How many people ever got
zapped by pushing a plastic power button?

It happens. Perhaps there was a problem with the set that allowed one part of
the switch to become energized. Those switches do have some metal parts,
including some on the exterior, and it's possible that those parts may have
been in circuit but not at ground potential.

But, I do agree. This is a weird occurance. What TV are we talking about
here? - Reinhart

Years ago, working for Cir Cty, I came across a Toshiba that would arc from the
dag to the speaker frames, which would energize the cabinet enough to present a
noticable ( and painful) charge to the speaker covers; some extra ground wires
and a good cleaning of the CRT bell solved the problem...