if he wasn't an experienced servicer , it may have been a little of both.

although i know of some tv techs that won't touch a game monitor.
which , i find amusing as there really isn't much difference from a tv ...

do try to find the alledged burnt part before u fire it up .
and/or just be ready to kill it - quick .........................................

loss of vert may have just been the output ic , diode(s) perhaps a fused resistor, caps
a discrete output has more components ( transistors ) but , essentially the same
type of failures.
qrz