Looks like you need the service manual. I don't have access any
longer.
Back in 2002 I was full aware of the problems Toshiba was having with
the convergence modules in those sets, and they were paying for a lot
of out of warranty replacements at that time. I was probably doing 1
or 2 per week with this failure for about 1.5 years back 3-4 years ago.

You did not answer the question of whether it was getting all the
correct signals.
I2C and data buses and power is only part of it, what about the pulses
from the vertical and horizontal circuits?

Add this web sites home page to your favorites:
http://www.eserviceinfo.com/equipmen...Toshiba_2.html
The tz50v51 service information should give you the basics on getting
into the convergence mode and doing a reset, if your set has additional
screen modes 480p, widescreen, etc, you will need the full service
manual on how to get into each mode to adjust the convergence.

FYI if this fixes the problem, you also need to buy the screen overlay
(or make one) for each mode to do the geometry adjustments. Same would
go if you could have replaced the main PLC/EEProm ic in the module. I
am not even sure you can buy that part from Toshiba individually,
certainly buying it generically won't work as it won't have any of the
programming information preloaded.

This is one set that it would probably be much less expensive having a
Toshiba Warranty authorized servicer repair as they should already have
all the overlay jigs and service manual on hand. This is your first
Toshiba RPTV from that era with a convergence module issue? Given the
high failure early on, I would bet that any Toshiba authorized servicer
that does any kind of volume for them has all the jigs and information.