"Fulcro" ha scritto nel messaggio
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"Fulcro" ha scritto nel messaggio
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Hi all.
This set is dead apart for St-By led blinking. Someone told me was a
flyback
transformer fault, so I replaced it but subsequently I realized that the
fault wasn't on the deflection section...
[cut]
Anyone have a clue?

Hi all.
With a deeper analisys, I realized that the SMPS isn't switching
correctly,
[cut]
What can I test?

After a revision, the SMPS seems to work "almost" well, since the +5V are
still absent.
Trying to turn on the deflection, is audible the SMPS that works more for a
second, then backs to Stand-By. All lines output from the SMPS are at a
correct level, either in Stand-By and when the set tryies to start.

141V is present (~60V in St-By mode)
+24 present (~8V in St-By mode)
-24 present (~-8V in St-By mode)
+5V St-By present (since it is stabilized by a 7805, is constant)

The only fault seems to be the +5V line that powers various section:
digiboard, PIP, source select and so on.
What the heck could it be blocking this line?
Just this line is terrible to follow on the schematic!!!
I'm sorry for continue posting on this fault. but is much important and the
D16 chassis seems to have no fault tips document all over the net...
Thank you very very much for any tip.
Fulcro


P.S.: after a minute or so, the SMPS seems to try to go high as deflection
would start, changing the signals from St-By mode to On mode, but this
happens also without pressing any button on RC or TV.