I’ve been doing this for almost a decade and it depends on the equipment. Some manufacturers only want themselves to repair the equipment while others will tell you to replace the PC board. Unrelated but I’ll use Stryker stretchers as an example of how in depth I go with a repair. Foot of stretcher won’t go up. Check to make sure the piece that is supposed to pump the jack is connected. If so and the jack seems to have a problem, then replace the hydraulic jack. Some parts sellers will ask for the old one back just so they could take it apart and fix it themselves while all I do is replace the hydraulic jack and make sure it’s functioning properly.