They are cheap gts but on that model the psu looses the 5v rail due to the caps drying up,it's one fault documented in the service manual.
Vestal psu's used in most brands are well known for their poor JH caps,and are easy to test with meter or scope only three lines of power.
Main or x'y sustain faults are mostly ic driver and fet's related problems or buffers and in most cases it's better to change the board out because I agree with you about the domino affect.
But saying that mate most sets these days have over voltage/short protection circuits that shuts the sets down,so none of the other boards are damaged.
A psu or main board are only about 30 quid each for this chaps monitor,so it's a cost effective repair but he will have to set the voltages to the correct specs,but it's voltage potentiometers and voltage for the rails are clearly marked on the board.
I use this site because I buy big screen panels from eBay and repair them,nowt to do now at my age plus it keeps me occupied :).
http://www.lcdtvparts.co.uk/index.php
e manno, September 2013