Quoted from JKnPA:
So wire# 30 is actually the Common or Return that is being
used to energize the various Units and steppers. I was thinking it was the HOT side and wire#70
was the Return.
yup, wire 30 is the common / return wire.
Quoted from JKnPA:
I understand how the circuit works from the Relay switches down to the SEARCH and REPLAY index
coils. I was having a problem of when EXACTLY the search Relays Lock-On. They Lock-On when the
Search disc passes over the Line defined by the Balls in the holes ? Does it take more than one pass
or should it happen the first time?
the search relays lock/stay powered only when the search wipers are stopped from rotating. It's supposed to happen immediately, but there's variables caused by the physical components and movement that can screw things up.
short answer is:
1] win scanning - closed playfield hole switches cause search relays to power
2] win detection - closed search relay switches cause search index coil to power and immediately stop the search wipers on the winning rivets
3] payout start - replay cams release and credits are adding to the replay register
4] payout ends - replay counter unit steps up enough times to disconnect circuit to the search index and replay cams index coils
5] no extra credits added - when all is right, no additional credits are added after the search index coil loses power
--- can't recommend reading anything below here ---
referring to the diagrams on manual pages 128 and 129, when the search wipers are rotating clockwise from the diagram position, the wipers contacts at position 0 move towards position 49 and you can see the ABCFG wiper fingers are going to touch rivets that are connected to game wires. Those fingers are the reference ones with a red mark on them, and looking at the chart on page 129 you see at position 49 card positions EFMNW are being checked.
the card positions are lettered because the actual playfield holes connected to those positions changes if you rotate the squares or move the lines.
the wiper contacts won't hit all the rivets at position 49 at the same time, but eventually the wipers will all be on rivets. At that time any search relays that are going to power (because there's a ball in that hole position) should be powered. The switches on those search relays are closed, and that in turn powers the search index coil which snags the metal ratchet and hopefully stops those wiper contacts from rotating off the rivets.
the search wipers are held in place for the duration of the payout.
so what can go wrong?
1] poor wiper contact -> rivet connections
2] poor/wrong slip ring hub connections
3] poor connection from a playfield hole switch to search disc rivet
4] in the case of beach time, poor connections in the squares/lines units which break the  path
any of those happen and search relays don't power or power intermittently. Holding the search wipers on the rivets that should detect the win lets you see if the search relays are powering, and using the chart on page 129, you can tell which search relays should be powering.
assuming the search relays are powering, the next thing you need is the search index unit to power and stop the search wiper rotation. How many ways can that go wrong ... :
5] dirty/misadjusted search relay switch contacts
6] bad connection anywhere in the path from those search relay switches to the search index coil. Could be more wiper connections on the search disc, score units, replay counter units, or relay cams index switches.
7] the search index coil is powering, but not stopping the wipers
check for  first. You'll see the search index unit power and let go. The most common problem is the search index unit needs to be loosened on the metal shelf and nudged toward the backglass a little. What's happening is when the ridge on the search index armature grabs the ratchet tooth, the wiper contacts are falling off the edge of the rivets. Moving the whole search index unit forward stops the wipers before they've rotated so far clockwise....but you can go too far. Move the unit too much and the ridge slams onto the top of a ratchet tooth and gets kicked away long enough to miss the tooth it was supposed to grab.
if the search index coil is doing nothing and you check the coil itself is ok, the easiest way to debug this is just jumper wire 45-6 on search relay #3 to one of the three "outputs" of the search relay switch maze AND below the routing back through the search disc wipers. Wire 61-3 is good because it doesn't go back thru the search disc, but if you want to look at 3-in-line or 4-in-line, connect the jumper from 45-6 to the wires going into the top of the score discs on the schem.
with the jumper on, you don't care that the search relays are flapping. You should have a closed circuit path from wire 30 all the way to search index coil, so if you put a meter probe on wire 70, you can poke around everywhere along the path from wire 30 to 15-2 and see where the 50V drops/disappears.
if you want to be super lazy, just connect wire 30 directly to the score disc wires (e.g. 54-3, 83-8 or 61-3 on the yellow score disc). If you still have no search index coil powering you know the problem is further down the schem and the circuit should be always closed.
generally you poke at easy places to get to and someplace in the middle of circuit first then work your way up/down. If you need to see voltages on stuff under the playfield, it's often easiest to poke the plug connections first to see if you need to go under there to check stuff.
if the search index is powering and stopping the search wipers on the rivets, but the game just sits there doing nothing...
8] the relay cams index unit didn't get powered to release the replay cams.
9] one credit gets added and the search wipers release. The process repeats adding one credit at a time.
 is pretty easy as the only thing that can cause that is a bad coil, a search index unit switch not closing, or a mechanical issue with the index unit.  is either an issue with a power resistor on the search index coil, dirty/misadjusted replay cams index switches, a bad replay register step-up coil causing large current surge, misadjusted switches on search index unit
if the replay cams are spinning, you almost certainly have credits being added and you've only got a couple hurdles left.
10] runaway payout / payout never stops.
11] payout stops early
 is usually a bad switch in the replay cams stacks. Some payouts will work right because they use different switches. The chart on manual page 126 shows which switch is being used to step up the replay counter for the win.
 is usually bad wiper-> trace connection on the replay counter disc. Payout typically stops when the wipers have stepped off a shorter trace. Note that in many cases multiple traces are connected back to wire 30. The longest trace terminates the payout when the wipers step off.
no extra credits
12] payout rounds up to a consistent multiple too much
almost always misadjusted replay cams index switches being closed when the cam locking pin is riding on the cam edge after the replay cams index coil loses power.