Hi again,

Some time ago I asked for schematics on my Samsung Syncmaster 531T
monitor as the backlight had gone out.
I have now pinpointed the fault to one side of the dual inverter.
I changed two faulty transistors that drove the output transformer.
Then the backlight worked for about 5 minutes, when it started
flickering and went off again. The worrying thing this time was that there
was a distinct smell of burned electronics around the transformer this
time....
Now the transistors are OK, but the backlight goes on for about 1 second,
then turns off, probably some protection circuitry switching off.
It seems like only the backlight of the part of the inverter that originally
was OK lights up.
One of my questions now is:
Can the CCFL tube fail in a mode that burns the output circuitry.

The inverter consists of two identical "channels" of which one seems OK, so
I can compare the readings when measuring it, but I cannot really find any
differences. I have also tried to connect the CCFL:s to the other
tubes channel and then that part turns on for the 1 second period. This
seems to indicate that the CCFL i OK ?

Any hints on where to start looking. I would buy a new AMBIT inverter, but
there seems to be no way of getting them and I am also worried about the
possibly faulty CCFL destroying the new one too.

--
Dag Nygren email:
Oy Espoon NewTech Ab phone: +358 9 8024910
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