CRT TV Blowing fuse

[[email protected]]

1995 27in Quasar made by Panasonic blew fuse. Not hit by lightning as
other devices not hurt and owner home when happened. Very handy and
trying to fix myself. Online indicates high probability degauss
posistor. Trying to disable per instructions. What does this look like
and where might it be located? Other suggestions? Thanks

 

[Jerry G.]

Because of the nature of your question, you should not be working
inside of your TV set.
This involves servicing the power supply section. The voltages and
current levels used in these TV sets can be dangerious. If not
properly serviced, there is also the chance of fire hazard, and safety
issues.

Usualy, a blowing fuse is from failed components that are causing the
pulling of too much current. Proper trouble shooting is necessary to
service the set, and get it working again.

I would suggest you find out who the local Sony service rep is for
your area, and let them give you a quotation so that you can make an
intelligent decision if the set is worth to be service.

Usualy, when a set is more than about 5 to 7 years old, they are not
worth to service. There is a chance for other things to fail.


Jerry G.

 

[b]

Jerry G. ha escrito:

Usualy, when a set is more than about 5 to 7 years old, they are not
worth to service. There is a chance for other things to fail.

thats a bit pessimistic jerry. I regularly fix tvs many of which are
older than that vintage and have very few callbacks. Provided it's
given a good once over, especially checking soldering and caps, then
theres no reason why it shouldnt last a few more years.
In this case it would be silly to toss an otherwise good tv for want
of a posistor worth about 1€.

To the OP: look for a little 2 or 3 legged cube or small rectangle
very near the mains input point on the main pcb. This is the posistor
- what you need to check. ( nearby there will be a plug with leads
going to a cable with what looks like black tape, wrapped round the
outside edge of the tube.)

Before digging around, unplug the set and leave for a few days so the
mains capacitor will have discharged. (best not to touch it just in
case). Desolder the posistor and try the set again. I would remove the
fuse and solder a 60- 100 watt bulb across the terminals. if it glows
very bright then you still have a dead short. if it flashes then goes
out then you've probably found the fault.

good luck and be careful. Ben-

 

[[email protected]]

Jerry G. ha escrito:




thats a bit pessimistic jerry. I regularly fix tvs many of which are
older than that vintage and have very few callbacks. Provided it's
given a good once over, especially checking soldering and caps,  then
theres no reason why it shouldnt last a few more years.
In this case it would be silly to toss an otherwise good tv for want
of a posistor worth about 1€.

To the OP: look for a little 2 or 3 legged cube or small rectangle
very near the mains input point on the main pcb. This is the posistor
- what you need to check. ( nearby there will be a plug with leads
going to a  cable  with what looks like black tape, wrapped round the
outside edge of the tube.)

Before digging around, unplug the set and leave for a few days so the
mains capacitor will have discharged. (best not to touch it just in
case). Desolder the posistor and try the set again. I would remove the
fuse and solder a 60- 100 watt bulb across the terminals. if it glows
very bright then you still have a dead short. if it flashes then goes
out then you've probably found the fault.

good luck and be careful. Ben-

Thanks. Would the device have markings like 5ROM then circle m57.
Plastic box taller than wider. There's a few devices between it and
line cord. Appreciate the safety comments and help. Set unpowered for
4 days. Would like to use a digital volt/ohm meter instead of light or
fuse? What should I look for? Voltage, amps, ohms? Thanks again.

 

[me]

[email protected] wrote in @l53g2000cwa.googlegroups.com:

Thanks. Would the device have markings like 5ROM then circle m57.
Plastic box taller than wider. There's a few devices between it and
line cord. Appreciate the safety comments and help. Set unpowered for
4 days. Would like to use a digital volt/ohm meter instead of light or
fuse? What should I look for? Voltage, amps, ohms? Thanks again.

To test if it is the problem you could unplug the degaussing coil and see
if the fuse still blows.

 

[Michael Kennedy]

*Snip*

Would like to use a digital volt/ohm meter instead of light or
fuse? What should I look for? Voltage, amps, ohms? Thanks again.

You are misunderstanding the purpose of the light. The 60-100W bulb should
be wired in place of the original fuse in the tv so that it limits the
current to the set and works as a resistor in case the fault still exsits.

It sounds that you probably need to do some more learning before you jump
into working on television sets. They can be quite dangerous.

Read this
http://www.repairfaq.org/sam/safety.htm

- Mike

 

[[email protected]]

*Snip*


You are misunderstanding the purpose of the light. The 60-100W bulb should
be wired in place of the original fuse in the tv so that it limits the
current to the set and works as a resistor in case the fault still exsits.

It sounds that you probably need to do some more learning before you jump
into working on television sets. They can be quite dangerous.

Read thishttp://www.repairfaq.org/sam/safety.htm

- Mike

Thanks. So I get a light bulb socket and run wire from fuse connection
to one side of light socket and do the same on other side. To your
point bulb acts as a resistor.

 

[b]

Thanks. So I get a light bulb socket and run wire from fuse connection
to one side of light socket and do the same on other side. To your
point bulb acts as a resistor.

that is true.
try the bulb, and unplug the degauss coil I mentioned earlier. plug in
tv, see what happens, but unplug damn quick if the bulb stays on.
-B.

 

[[email protected]]

that is true.
try the bulb, and unplug the degauss coil I mentioned earlier. plug in
tv, see what happens, but unplug damn quick if the bulb stays on.
-B.

Thanks. This is a chassis ALEDC246. Have original blown fuse. How can
you tell slow blow from fast blow? Thanks