The only check I can suggest is "Is the standby light on?", as the
commonest problem is that the power is off at the wall or it has tripped
a breaker.
Either that or the remote control has a flat battery.
Sorry if that's not much help, but the local TV guys want an arm and a
leg to prize them out of the workshop nowadays. If they are passing this
way, I can have a quick look as they pass Longport, but my workshop days
are long gone.