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What exactly does "slow trip" mean?

T

Tov

with reference to televisions in particular?

Please excuse my ignorance. Would a standby light blinking once every
two seconds count as a "slow trip"?

thanks for any explanation.
 
A

Arfa Daily

Tov said:
with reference to televisions in particular?

Please excuse my ignorance. Would a standby light blinking once every
two seconds count as a "slow trip"?

thanks for any explanation.

Maybe. Depends on what the LED is signifying. If it's just the power LED,
and doesn't serve any secondary engineering diagnostic function, then it
could definitely signify that the power supply is cycling up and tripping
out repeatedly. This will often be accompanied by a soft 'ticking' noise.

Arfa
 
J

Jerry G.

The power supply may be in a failed condition, or there is a short
somewhere in the set. This would require proper troubleshooting, and
not guess work.

Take the set in for a proper estimate. It can be a challange for even
a skilled service tech to repair these types of faults.

Jerry G.
======
 
N

none

Tov said:
with reference to televisions in particular?

Please excuse my ignorance. Would a standby light blinking once every
two seconds count as a "slow trip"?

thanks for any explanation.

It sounds as though you might be talking about a circuit-breaker,
designed to "trip" only when a current overload has continued for a
given number of milliseconds.
 
T

Tov

The power supply may be in a failed condition, or there is a short
somewhere in the set. This would require proper troubleshooting, and
not guess work.

Take the set in for a proper estimate. It can be a challange for even
a skilled service tech to repair these types of faults.

Given the age of the TV (at least 17 years) I can't really justify the
expense. I'm prepared to spend my own time, though, in the hope that
it will be a fairly inexpensive fix, once identified.
 
A

Arfa Daily

Tov said:
Given the age of the TV (at least 17 years) I can't really justify the
expense. I'm prepared to spend my own time, though, in the hope that
it will be a fairly inexpensive fix, once identified.

It would first be necessary to determine if the power supply was
'self-faulting', or tripping as a result of detecting an over-current
condition on one of its rails. Without experience in the field, this may
prove difficult for you to determine, as sometimes, trip conditions can be a
little bit 'round and round in ever decreasing circles'.

Generally, self-faulting of the power supply is caused by faulty
electrolytic caps - which may be open circuit, short circuit or poor ESR -
short circuit secondary diodes, and occasionally more subtle problems in the
feedback circuitry. Reasons for overload tripping include short circuit HOP
transistor, faulty flyback transformer, faulty HV tuning caps, faulty E-W
modulator circuitry, faulty field output chip, faulty sound output chip, bad
joints in HOP stage and so on. To get any more specific help, you would need
to declare the make and model number, and then someone on here might be able
to point you at particular problems for that TV.

Also, I don't know what your experience level is, but if you are not used to
working with TV sets, and switch mode power supplies in particular, please
be very careful of your personal safety. These power supplies are connected
*directly* to incoming line power, and are potentially lethal, as in able to
cause death.

Arfa
 
T

Tov

It would first be necessary to determine if the power supply was
'self-faulting', or tripping as a result of detecting an over-current
condition on one of its rails. Without experience in the field, this may
prove difficult for you to determine, as sometimes, trip conditions can be a
little bit 'round and round in ever decreasing circles'.

Generally, self-faulting of the power supply is caused by faulty
electrolytic caps - which may be open circuit, short circuit or poor ESR -
short circuit secondary diodes, and occasionally more subtle problems in the
feedback circuitry. Reasons for overload tripping include short circuit HOP
transistor, faulty flyback transformer, faulty HV tuning caps, faulty E-W
modulator circuitry, faulty field output chip, faulty sound output chip, bad
joints in HOP stage and so on. To get any more specific help, you would need
to declare the make and model number, and then someone on here might be able
to point you at particular problems for that TV.

I'm glad you mentioned the field output chip - that seems to go at the
rate of once every 6 years or so on this TV, having been replaced
twice already. It's worth a punt, anyway.
Also, I don't know what your experience level is, but if you are not used to
working with TV sets, and switch mode power supplies in particular, please
be very careful of your personal safety. These power supplies are connected
*directly* to incoming line power, and are potentially lethal, as in able to
cause death.

Point noted.
 
T

Tov

It would first be necessary to determine if the power supply was
'self-faulting', or tripping as a result of detecting an over-current
condition on one of its rails. Without experience in the field, this may
prove difficult for you to determine, as sometimes, trip conditions can be a
little bit 'round and round in ever decreasing circles'.

Generally, self-faulting of the power supply is caused by faulty
electrolytic caps - which may be open circuit, short circuit or poor ESR -
short circuit secondary diodes, and occasionally more subtle problems in the
feedback circuitry. Reasons for overload tripping include short circuit HOP
transistor, faulty flyback transformer, faulty HV tuning caps, faulty E-W
modulator circuitry, faulty field output chip, faulty sound output chip, bad
joints in HOP stage and so on. To get any more specific help, you would need
to declare the make and model number, and then someone on here might be able
to point you at particular problems for that TV.

Well, I replaced the field output chip and the voltage regulator and
repaired two circuit board damaged connections in the vicinity of the
latter and it works! Just goes to show you can be lucky even though
you don't really know what you're doing. Thanks, Arfa.
 
A

Arfa Daily

Tov said:
Well, I replaced the field output chip and the voltage regulator and
repaired two circuit board damaged connections in the vicinity of the
latter and it works! Just goes to show you can be lucky even though
you don't really know what you're doing. Thanks, Arfa.

You're welcome, and the good bit is that now you do know at least a little
bit more about it, for when you next encounter a similar problem. Well done
on sorting it !

Arfa
 
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