Repeat - Pioneer TV update/help

Ok, here we go - with the B+ adjusted dead on 135V, I re-
installed the power board. As soon as I plugged in the set, the
relays
clicked, and then nothing. Last post I told you all three tubes were
lit, with faint raster. I unplugged the 8 pin socket that appears to
come from the convergence board to the PB. Plugged set in and it
powered up with 3 nice bright horizontal retrace lines - red, green,
and blue (convergence drifted?) across center of screen. The lines
were not real clean, but bright enough for normal raster I would
suspect if the vertical was working. I didn't bother adjusting
anything. Unplugged power cord, plugged this 8 pin socket back in and
plugged set back in. Hit power button, relays clicked (saw green
power
light on front panel), then shut down.
I did have the set powered up with this 8 pin connected once,
and got a picture, although it was very dark and grainy. I couldn't
reproduce this again, and didn't get a look at the proportion of the
raster looking at the tubes.
Now concerning the 8 pin socket and plug - the socket at the
power board has the following id's for each pin - -25, gnd, +25, PD,
HV para, P key, V ret, V in . Best I can see all these terminate on
the convergence board. There is a 4 pin plug on the convergence board
that have these 4 pins (-25, gnd, +25, PD). I got so focused on
checking solder joints on the covergence board, I never checked the
damn voltages at this plug before I left my buddy's house.
I am suspecting the PS may be fine, and the problem may be on
the convergence board (yeah I better check the -25, and +25 supply).
I
will do this next trip for sure. I hope this info clues you onto a
probable cause here. Until then I will check discreet components on
the convergence board since I brought this home with me, and find out
what the two big IC's with massive heat sinks function are. Is one
vertical IC, and other convergence? I've always seen 3 convergence
IC"s in big screens, but again I haven't been doing this for very
long.
Thank you once again for your help.

I have researched and found info on the STK4277SL (pincusion). I don't
know if it's bad, but don't know how to test except substitution. I
don't have the friggin schematic (another problem), but since the
-25/+25 voltages from the power supply tie to this IC, and a
malfunction of vertical may be causing the set to go into shut down,
would it be feasable to try replacing the IC based off the info I have
given? Thanks all for any suggestions.

 

I'm no expert on big screens, but I don't think a convergence amp bad
(that's what the 4277 is) would normally cause a shutdown problem.

Mark Z.