These games remember when the last time the switches were pressed. If after a few games they haven't registered the switch being pressed, the game asks you to adjust the switch. (the contact switches have metal leafs that you bend to make sure they're aligned properly). There is a switch at the entry to the ramp and I want to say 1 or 2 more on the ramp and at the end of each diversion. Some aren't really all that critical (for scoring or whatever), but really you'd want all the switches working properly.

So, long story boring, you can probably just bend the ramp switch leaf so that it's about 1/8th of an inch open.