[behringer]

You take them to someone who can do component level repairs.

And the basic hardware is more difficult than just the parts and these nuances can make certain parts expensive and rare.

You have to know all kinks of things like irqs, dos commands, memory layout, jumper settings, just an insane amount of stuff compared to modern plug and play equipment.

[EricE]

That insane amount of stuff was just par for the course back in the day. I still have my old spreasheets and technicians toolkit of 5.25" floppies with all the old school utilities (check it - I forgot about it until I came across my old suite of floppies while moving a few years back)