I ran into this myself a few times. Without the Sencore somehow you need to
excite the fly. With nothing connected to the anode output, shorting the black
wire to the normal ABL pin (not sure of the number right now, but it's the one
with the spark gap) will distort the waveform on a direct view fly, but not on
a PTV fly.

Doing this on a Sencore, you should get a "bad" indication with the short in
place. I don't know if it will show up on a normal flyback ring tester. It
would probably have to be excited to the point where it's putting out at least
600-700 volts to show up for sure. With lower voltages you might get false
negatives on some because of normal tolerances.

Let's put it this way, however you excite it, if there is any + voltage on the
black wire it is probaly the wrong part. You should have a negative voltage
there if anything.

Of course now a few of us have some flys in stock, now to figure out what
they're for. Of course they will probably work in many CTC169s but they might
put out a bit too much HV for a 27". I know this much, if you reroute the ABL
line as in a direct view and insulate the black wire a PTV set will run, but
you should disconnect the power to the HV booster board or it will be going
full blast trying to regulate.

I actually had to ship one like that in the past, the customer was getting to
be quite the hothead, but he was told about it. It was safe, but we told him
about, like when something blows up the image will bloom. As far as we could
tell, before we had this thing figured out, the focus voltage going into the
secondary of the HV boost transformer had caused it to fail. We are pretty sure
of this because in the end the only thing it took to fix that set was the
flyback. Of course we went through the lytics in the power supply and we
usually have a look at the 15V line on these, none of these other things were
the cause of failure.

JURB