Quoted from Pin-Pilot:
All those switches are on the same switch matrix column, along with Plumb bob tilt and start switch.
Since your start switch appears to be working the matrix transistor is fine.
Look under the playfield, find the Green/Brown wire (common to all 4 switches that are not working) and make sure that it is not disconnected somewhere. If you have a DMM check continuity on the Green/Brown wire as well.
Check your Plumb Bob Tilt #14 to make sure that is either working or not. I would imagine it is working since your start switch is working.
Ok so further intrigue, game came on this afternoon, all working, I played maybe 3 games and then suddenly in the middle of the final game the "pinball missing" message came up, so games works for a short period of time and then message displays, which almost suggests that once warmed up a loose connection appears ?
The Plumb Bob hasnt worked for a while (I assmed it was disconnected, turns out its there but there must have been a loose connection)
I looked through the manual and had found that the 4 trough switches, Start and Plumb Bob Tilt are on the same column they all have a common Green/Brown, so I had a look at the Coin Door Interface Board and looked at J6 Pin 8, Pin 7 and Pin 6, on loosening the connector all three cables came loose from the vampire teeth ... in fact they snapped off, suggesting that there has been an issue for a while.
I've tired reconnecting the wires by pushing them in Green/Brown to Pin 8 and Pin 7, Green/Red to Pin 6, I assume at least one connection is working as the Plumb Bob is now working (it wasnt before), the trough switches still aren't working, I haven't got the correct tool to push the cable in correctly, I need some version of the network Krone tool that I have.
It looks to me this may well be where my issue is, Start and Plumb Bob Tilt now work the other switches in the column dont ..
Added 15 days ago
Further update, cabinet works on first power on, game started ok, I then immediately checked the switches and they all work ok, tilt included, so all switches on the column with Start, Tilit, Troughs etc work fine, I then wait less than 30 minutes and try to start a game and I get "pinball missing" ....