Re: Star Wars - flyback suggestions?

On Mon, 17 Aug 1998, Dave Turner wrote:

> Well, it is definatly and Amplifone. I also have two HV boards with the
> red HV transformer. Plugged the first in and smoke everywhere. Found
> that VR1 is cracked and smoking. Put the second board in there, no
> smoke, but nothing. No neck glow or picture. Checked R12 on both HV
> boards and it's good. Where do I start to see if the HV transformers are
> bad?

        The way that I check is to get the board(s) up and running and
try to eliminate all other sources of the problem. That means
test/replace the two voltage regulators, and measure to see that you are
getting good +/- 24V on their outputs. Test/replace the BU406D. Check
to make sure you have AC on the base of the BU406D. If all these look
good, but you still have no HV, heater, etc voltages, it's a safe bet that
the flyback is bad. As an initial gut feeling, it looks to me like the
second board has a bad flyback (check to make sure it has +/- 24V, though)
because a bad flyback will result in nothing. No spectacular smoking
flyback or anything like that -- just nothing. If VR1 is smoking,
make sure the corresponding fuses and jumpers on the deflection
board are intact. I thought I had HV problems until I realized that a few
of the wire jumpers were actually open. This problem is documented in
Gregg Woodcock's XY troubleshooting FAQ.

        Voltage Regulator Failures and BU406D failures are pretty common
in my experience, so there's a chance that one of those boards might have
a good flyback.

Good Luck!

Joe
Received on Mon Aug 17 11:34:10 1998