https://pinside.com/pinball/forum/topic/whitewater-switch-57-not-registering
https://pinside.com/pinball/forum/topic/new-problems-with-whitewater

Check out some older threads that might help

Not sure I understand what you mean by this. Could you explain like maybe wiring or the switch does register.

Well you could start by listening to the switch when you push down. Inside the switch you will here a clicking when activated. Could compare to other switches to make sure nothing came apart inside.Still would not rule out bad switch but a start. The manual can be downloaded off ipdb and if you go into switch test it will show you the color wires associated with that column and row of switch 57 to check the wires since switches are daisy chained. Like the old thread says check diodes.

If it was my game I would replace the switch. I'm assuming you don't have replacements but order them now from pinballlife. They come with a diode attached for about $3.50 I believe. You are going to need them in this hobby.

In the meantime I would look at each switch on the areas I highlighted. Check the wires and the diodes to make sure none are broken off. These switches are daisy chained to one another. A broken wire at another switch could affect others down the row or column....like christmas lights. If everything physically appears fine test each one of those switches in "Switch Edges" in the test menu. You should hear each switch register with a beep and see it on the dot matrix display when activated. If one doesn't work it could be a bad diode at that switch impacting others (Switch 57) down the line.

Buy switch here.
https://www.pinballlife.com/microswitch-with-diode.html

If those options don't work it could be a switch matrix issue on the board. There are ways to test that also but you will need a diode and with a piece of wire soldered to the end. You can pull the switch matrix connectors (one for columns, one for rows) and touch the wire end to one and diode to the other and you should see the switches register in Switch Edge Tests. I don't think this will be a problem as it sounds like only one switch is out.
Wh20 Switch (resized).JPG

The easiest way to find out if the switch itself is working is to bring up test mode, and then bypass the switch with a small wire or paperclip. The switch does nothing but complete the circuit when triggered. If you bypass the switch by connectin the two areas where the wires connect to the switch with a paperclip or wire, you know it is an error with the switch itself. If it doesnt register, the error is elsewhere. Also, if there are any connectors on the wire that comes out of the switch... unplug them and plug them back in and test. Good luck!

Here’s someone fixing a switch in detail just thought it was kool.

https://pinside.com/pinball/forum/topic/microswitch-repair