Hi all ...
Star Wars lives!
Thanks to everyone who gave me suggestions as to what was wrong with my
Amplifone.
When I scoped the outputs to the deflection coils I was getting 50v Peak to
Peak (ish ... my scope is old and probably was last calibrated when the SW
was made!) on the X coil and 12v Peak to Peak in the Y coil. I verified
the levels going into the deflection board from the game board and they
were fine. The spot killer was now coming on occasionally so the fault had
progressed!
Last night I spent what seems like an age verifying components on the
deflection board. About half way though I'd pulled the three 2N3904's in
the Y amp stage (Q2, Q3 and Q4) one of them was open between the emitter
and base (in both directions) I replaced all three .... and hey presto ...
it works!
Phew ... not need to worry about the tube being bad now!
I go back today and replace all the 2N3904's to be sure it wont fail again.
Once again ... to all those who helped me ... thanks!
Dave Langley
www.robotron-2084.co.uk
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Received on Sun Oct 27 02:31:30 2002
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