Looks like a diode to make sure the hold relay doesn't activate backwards... or something like that?

I would assume you can just replace with a normal diode of the correct or higher voltage rating. I've never seen a diode look like that before.

It's a sand resistor.

You can pick one up at an electronics supplier. Look on the schematic and find the proper rating for it. I looked at Capersville on IPDB and it's a 15 ohm, 5w resistor. This is probably the same. My Bally Surfers has a resistor on the hold coil also.

Hi Keith
I do not have an "Cosmos" - ipdb has no schematics. I show stuff from GOTTLIEB (Far Out) and I show stuff from Bally Rockmakers.

In post-1 You write about "soldered-on to Hold-Switch" - I read "Hold-Relay". EMsInKC said it --- a resistor - a rare, somewhat special resistor: First the 15 Ohms (unusual) , second the 5 Watt(s) (unusual), "unusual" as in electronics like radios the resistors used: Mostly have some Kilo-Ohms and maybe a tenth of a Watt.

Can You play the Cosmos ? When playing: Can You shake the pin so the pendulum tilt closes and a "Tilt" happens ? (You loose the ball - You may loose the whole game)

I believe - At the time of manufacturing the pin: Bally wanted to save money by "We do not mount an conventional Tilt-Relay (saves money as we do not use such a relay) - we do a trick and (only) use a cheap resistor.

(Conventional) In the first JPG I show "A" is the schematics***, "B" shows "You happily play a ball - the H-(Tilt)-HOLD-Relay steady, continuous pulls and so keeps the pin running - 'Coil on H-Relay gets current through green lines' ". "C" shows: You bang a tilt, pendulum-tilt-Switch closes - T-Tilt-Relay gets current, T-Relay pulls-in and so opens the "T-Switch, in line of feeding H-Relay" - H-Relay looses current and let go - and so moves its Make-and-Brake-Switch to 'red state as shown'.
"D" shows as You must look how the (tiltet pin) steps down the Bonus-Ladder - punishes You. See that in "D" there is no possibility for electricity to flow to Coil on H-Relay (?).
"E" shows - The pin says: Enough punishment - I (the pin) activate the O-Outhole-Relay to kick a new ball over to the Shooter-Alley - and by O-Relay activated: A Switch on O-Relay (my red dash in the switch) closes - current can flow so H-Relay can pull-in - and You happily can play the next ball (we have returned to "B").
The above written is "conventional way" WITH a-tilt-Relay pulling-in and by pulling-in: "Self-Hold-Feeding-Line on H-Hold-Relay will be cut".

The second JPG shows: You happily play a ball - current can flow "A, B, C, D, E, F, G, H, I" - the Hold-Relay steady, continuous pulls and so keeps the pin running.
You bang a tilt so "K" closes - a Freeway / Bypass is established - ALL electrons bypass the Hold-Relay so Hold-Relay lets go and opens its "named 'G' Switch" - Tilt takes place - I assume in Rockmakers it is an "Game-Over-Tilt".
Look at "burgundy-red / violet line and switch": Closing the "violet L-Switch" would also make an bypass (on Hold-Relay) - BUT as this would be a "short": The FUSE (my green 'B') would BLOW.

So the trick with the (green 'F') Resistor is: It must have "low, few Ohms" so You happily can play as the Hold-Relay DOES steady pull. BUT also the Resistor must have "high, many Ohms" so when You bang a tilt and bypass the Hold-Relay so (no more current to Hold-Relay-Coil) the Hold-Relay let go (and this means TILT): RESISTOR let NOT pass so MANY electrons that the fuse (would) blow. I believe: Bally tried different combinations with "Hold-Relay and Resistor" and then said "Hold-Relay with 100 Ohms" and "resistor 15 Ohms, 5 Watt(s)" WORKS - lets use this combination.

Want to consider (?): Let everything "as is" and simply play Your pin.

If You want to WORK / REPAIR: FIRST buy a new resistor - THEN You can work on the pin.
I believe: The preowner has fumbled on the Hold-Relay - maybe have cut "feeding wire to the coil" and maybe BENT switches on the Hold-Relay so the pin runs "Hold-Relay is not pulling - but, hihi blades on switches are BENT so we can play".

schematics***: We must accept the fact: Williams, Gottlieb and Bally show the drawing / schematics in an very strange / very specific state: A game for one player is started, reset is done, ball is delivered to the shooter alley - THEN "110 VAC line cord" is UNPLUGGED.
Greetings Rolf

zFar-Out-Work-03 (resized).jpg

zRockmakers-Work-01 (resized).jpg

Hi Keith
thanks for the flowers - I could buy within some 7 years my "then loved, Arcade-room times" pins.
About Your problems - You do not have an schematics, You do not have a manual - buy these prints. First: I believe "To every pin there should be the schematic and the manual", second: I doubt that I can help troubleshooting (not having the chance to look at snippets of the schematics YOU post in pinside). Closest in time (4 player pins) to "Cosmos" are "Rockmakers" and "Gator" - I looked them up in ipdb - there are differences in the schematics - and so the question is "Cosmos is like Rockmakers" or "Cosmos is like Gator" or "Cosmos-Solution is different to BOTH" ? (((And: knowing the wire-colors to look-up in the pin would be very "nice to have")))

Just some "general" thoughts - When You play without that "resistor to come" - after one minute of playing, again after 3, 5, 10 minutes: Toggle-off the pin (Safety Reasons), then carefully put a finger onto the Coil on Hold-Relay - does the Coil gets REALLY hot ?

When the pin has done the reset - does not want to kickout the ball - look for a "Ball-Return-Relay" - carefully touch*** the armature / anchor plate and PRESS - simulate "Coil pulls-in" - does the pin NOW kicks the ball out ?
touch***: Because of Safety Reasons: Use an wooden stick --- consider / remember "Cosmos has 110 VAC in the pin - has 48 VAC in the pin - has 6 VAC in the pin" - do NOT touch wires, do not touch solder-lugs.

Not changing to next ball: Look at Coin-Unit and look at Player-Unit - has a wire broken-off ?

To talk in detail (about the resistor and) the "activation of Hold-Relay": I need a snippet of the place in the schematics. Greetings Rolf

Hi Rolf,

As someone relatively new to EMs and their engineering, I really enjoy learning from your posts.

Your method of tying the written descriptions to the labeled schematics is very helpful, and thank you for taking the time to create those graphic markups and explain the related logic.

Best regards,
T