Hi bonzo71 +
I do not say "there is a fault in Your friends 'Volley' ". I say "maybe in Your friends 'Volley' the Self-Hold-Circuitry on the Pop-Bumper-RELAY is no good - not working (?)".

I do not have the schematics "Volley" - I show it on "Royal Flush" --- see the JPG. In a fully running Royal Flush happens: The ball rolls to the bumper and closes "my brown-1 Switch" - the relay (brown 2) actuates - it closes several switches (3a, 3b, 3c) --- "3a" makes the "4a" pull - "3b" makes the "4b" pull - AND THE closing of ("3c") Self-Hold-Switch makes the relay ("Yes, the 2") pulling, pulling, pulling (and therefore closed are 3a, 3b, 3c) UNTIL the plunger on the Pop-Bumper at the end of its travel opens "5" --- end of feature, everything quits pulling.

Now comes the "maybe fault": When "3c" is faulty always open or when "5" is faulty always open or when a connecting wire has broken-off in this circuitry: The period of time of "pulling 4b" is (grace shot of the ball) shorter with the fault in the pin (compared with an fully running pin (grace shot)).

Want to do a test to check for "the maybe fault is in the pin" to prove right or to prove wrong (?):
Locate the Pop-Bumper-RELAY - locate its Self-Hold-Switch (3c) - easy to be found: A short wire runs from one side of the Pop-Bumper-RELAY to "Switch mounted on the Pop-Bumper-RELAY" - THIS IS THE (3c) SWITCH. Sneak-in a stripe of paper inbetween the contact-point / blades to make this Switch ALWAYS open (Yes we sneak-in a fault) --- then play the pin - watch and feel the action on the Pop-Bumper. After this test You may say AAA: I see and feel the Pop-Bumper acts different (with the sneaked-in stripe of paper) --- or You may say BBB: The Pop-Bumper acts exactly the same as before.

When You say "AAA": The maybe fault is NOT in the pin --- when You say "BBB": Chances are that the (maybe) fault is in the pin (((manipulating an already broken connection to "broken" has no effect - broken is broken))). Greetings Rolf

0Royal-Flush-Work-19 (resized).jpg

Hi bonzo71
please write about "the Alternating-Relay in Volley does ..." - using this picture http://www.ipdb.org/showpic.pl?id=2743&picno=47939 .

The "maybe fault" in Your friends pin made me to study the schematics on my "Far Out". Far Out also has an Alternating-Relay (named A-Relay) - see http://www.ipdb.org/showpic.pl?id=823&picno=52839 - The A-Alternating-Relay turns-on / turns-off the bumper-lights and changes lights / making points on many places on the playfield. There is a Mini-Stepper (named I-Advance-Unit-Relay) - in positions 0, 2, 4, 6, 8 the A-Alternating-Relay is made pulling --- in positions 1, 3, 5, 7, 9 the A-Alternating-Relay is made non-pulling. The I-Stepper is actuated when the ball hits the left or the right bumper. Also the I-Stepper is actuated when the ball rolls over the Rollover-Button (a bit below the Center Bumper in the ipdb-picture).

The tests giving result either "AAA" or "BBB" (see post-10) actually are tests "bulls-eye hit" - "hit" - "grace shot" - "very-grace shot" - "very-very-grace shot" - "very-very-very-grace shot" - different lengths in time for a switch to be closed - closed for to let current flow to "Coil on Mini-Stepper".
In my "Far Out" I can do these different (length of time) hits by pressing the Rollover-Button for long or for short or for very-short.

In Your friends pin You can do such testing (different length of time) by using two clipped-on Jumper-Wires --- see the JPG in post-10 - see "my brown 3b - 'B'-Switch" - a Jumper-Wire clipped-on on the left solder-lug of the switch and another Jumper-Wire clipped-on on the right solder-lug of the switch --- THEN You hold together the other ends of the two Jumper-Wires --- long in time or medium or short in time - WHAT is the Mini-Stepper doing ?

(words from a dix) "riddle / conundrum / puzzle / brain twister": The reason why Gottlieb used the wiring "my brown 'choosen solution' " and not the wiring "second way of wiring" --- the reason is ...
Greetings Rolf

0Far-Out-Work-31 (resized).jpg