Attn: ZZac - Pioneer TV update

I haven't had time to check the raster as of yet since I have been
working 7/12. I have adjusted the B+ voltage back down to 135V, which
you were dead on about, since it says "135V adj". This has brought the
voltage down on the Hot collector to 101V, from 119V. The darlington
reads 135V on it's collector, and 101V on both emitter and base
(crossed by a small diode). Looks like this darlington is supplied by
135V from another winding on the flyback. The darlington emitter ends
up at the Hot collector via low ohm resistors and a diode.

There are two test points on the board. Both say "PD 135V". I traced
this all the way to an 8 pin socket that says PD at this terminal.
Other terminals are labeled +25, -25, gnd, etc. I'm not sure what "PD"
stands for, but both test points read 0V. Both points are electrically
connected and tie to either the base or emitter of a small transistor.
The other two legs read right at 135V.

This may be normal since I have the power board on my dining room
table out of circuit. The rest of the set is about 15 miles away. I'm
not sure I mentioned this in the original post. You are exactly right
in this being a real mother to figure out. I have only been working on
sets for a couple years (self taught) and with this groups help, and
have never seen a power supply like this. I try to stay away from big
screens because of the hassle of going back and forth to the set. I
already have a 46" Mits in my kitchen that is trash since I can't get
a replacement tube.

Again, I will post follow ups as I get info. This set belongs to
friends that have seen better financial times, and I would love to get
this thing going for them since they can no way replace it. I'm
willing to bite the bullet on the majority of parts costs. My time
will be free as usual. Thank you for your input and interest.

.

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