That sounds like an easy thing to fix, but the whole power-on architecture was a baffling Rube Goldberg device from the button on a small support PCB to the front panel PCB to the PC plug-in card to the power supply. I've never seen anything like it.
I disclosed the flaw to the buyer (the price was very low) and he was excited to have something to work on. :-)
That doesn't leave a whole lot of alternatives, Mr Lecroy.