Chassis HV8SA

All,

Originally monitor would not power up, made ticking sound only. Thanks
to postings found here, found several bad parts around HOT
(q855,q719,q550)

Now monitor has no horizontal sync, and vertical is top half of screen
only, with horizontal white line in the middle. Have found and
replaced bad C408. All diodes in vertical section check OK.

Anybody have any suggestions on what to check next? Also, I found it
very difficult to probe anything on the chassis to make measurements.
Is there a trick to making this feasible?

I was going to offer to trade schematics for advise, but I'm instead
just going to post a link and trust in the kindness of the readers.
It's for a panasonic monitor, but it uses the same chassis.

http://rv6llh.rsuh.ru/panasonic/TX-D2162.ZIP

Thanks in advance for all assistance.