Board # 3141vmnp478, Zenith has listed as module level repair only.

We bought over 40 of these last year and they are now out of warranty.
During warranty approximately 50% of them failed with the same symptom:
Bottom half of picture was stretched and distorted in two or three
distinct bands with black lines of varying size. The odd part is the
black lines get wider toward the right side of the screen.

Have already esr checked all capacitors in the vertical and jungle ic.
Jumped across all capacitors in vertical. The distortion is clearly
visible in all the vertical waveforms, including the drive out of the
jungle, but the jungle usually has a feedback line so it may or may not
be the jungle or the output circuit.

No service manual on hand. The information available is limited to the
installers menu. We have tried to order and get a service manual out
of Zenith for several months and it has not been forthcoming.

Has anyone seen a similar odd vertical looking problem on the latest
model Zenith/Goldstar sets and found the problem? If so what was it.

TIA David