Thank you both for information and the links. I did find the presentation and the Sam's manual, I also bought factory service manual for 9L37 chassis.

Tom, thank you for the point no repairing the board without removing it. I'll definitely give it a try. If I can lift that board by a couple of inches off the chassis with just desoldering the ground lugs and a couple of wires, that would be amazing.

EDIT: I didn't have the Beitman manual. This is great additional resource. Too bad they all have 9L38 board layout, which has a different pin connection numbering, but 9L37 layout is still well visible from page 2 overall TV layout.