Panasonic TX-29AD1DP faulty degauss circuit

[Mike Smith]

Hello All,



I have a Panasonic tv (model TX-29AD1DP) with a faulty degauss circuit. Does
anyone know how I could distinguish which is the degauss circuit?



I posted this fault a little while ago and someone (I think its was someone
named Alain Beguin but can't remember) told me how to identify the degauss
circuit, but unfortunately the message timed off the newsgroup before I
could print or note down the email address of the person and ask how to
correctly identify the circuit.



Also, does anyone know where to buy the replacement components in the uk?



Thanks,



Mike



[email protected]

 

[scada]

Hello All,



I have a Panasonic tv (model TX-29AD1DP) with a faulty degauss circuit. Does
anyone know how I could distinguish which is the degauss circuit?



I posted this fault a little while ago and someone (I think its was someone
named Alain Beguin but can't remember) told me how to identify the degauss
circuit, but unfortunately the message timed off the newsgroup before I
could print or note down the email address of the person and ask how to
correctly identify the circuit.



Also, does anyone know where to buy the replacement components in the uk?



Thanks,



Mike



[email protected]

The degauss circuit consists of a coil of wire that surrounds the back of
the CRT (picture tube). A PTC thermistor is connected in series with the AC
line and this coil. The old sets that turned on with a power switch,
supplied the AC to this circuit. The newer sets turn on with a signal sent
to a microprocessor that wakes it from a sleep mode. Then in some fashion,
it energizes the AC to the degauss circuit. If you need that kind of detail
you will probably need to buy a schematic for your model set. In any case,
AC is introduced to the coil through the thermistor (very low resistance),
providing a magnetic field through the coil around the CRT. When the
thermistor heats up, it's resistance increases, lowering the current to the
coil to a negligible value and removing the magnetic field.

 

[Art]

Panasonic has been having an issue with the DGS Thermistor and Control Relay
in some applications. Finding the DGS Coil and where it connects to the main
board will put you right where the Thermistor, Relay, and control transistor
are located.