Comet Pinball Jet Bumper Lights

(Topic ID: 230701)

Comet Pinball Jet Bumper Lights

By PinballGurus

16 days ago

Topic Stats

  • 29 posts
  • 5 Pinsiders participating
  • Latest reply 12 days ago by yzfguy
  • No one calls this topic a favorite


Linked Games

Topic Gallery

There have been 13 images uploaded to this topic. (View topic image gallery).

CA38C6C6-8126-4C0A-BB41-66B9C76527CB (resized).jpeg
C249740D-064E-4E0C-89EB-C4A306FDC207 (resized).jpeg
D394F621-7E22-4274-A245-7771CC2F9EB7 (resized).jpeg
6F184FF7-8BE5-4781-ACC8-AF9C8297BF08 (resized).jpeg
994F30C6-B444-47BD-B7EA-38A976A20C58 (resized).jpeg
080799C9-58FE-43EF-B14A-03A2F250254C (resized).jpeg
AA1BFE54-84D9-4911-9CA6-7C38AF3BD20A (resized).jpeg
B8B9C92B-5EDD-44E7-ACAA-0B96BDB154FF (resized).jpeg
0C714C34-B59F-4B0C-A798-C0F5B72A680C (resized).jpeg
84CE65BA-7E8C-4284-90DC-806E4B3BC673 (resized).jpeg
3EBCC0E7-6A33-4089-A431-7A355FD735BC (resized).jpeg
5121589A-95F3-4D73-B4D5-FB59646B5743 (resized).jpeg
F0314E6D-CF77-402E-A76A-052341A52E18 (resized).jpeg

#1 16 days ago

So I was having an issue with a loose bulb on one of my jet bumpers and like a newbie was attempting to make it fit and shorted something, now the three jet bumper lights have stopped working; the bumpers work, but the lights don’t. I replaced the relay on the light board and that didn’t help; same issue. You would have thought I blew a fuse, but all other G.I. (General Illumination) lights work, it’s only the jet bumper lights. I’ve checked the voltage on the socket and it’s reading 4.5 volts on both sides of all the sockets, but the lights still won’t come one, which is really confusing me??? Any ideas of what else this could be? I assume there’s another fuse somewhere that controls just those three lights or??? Thanks in advance!

#3 16 days ago

I think its Williams Comet

OP are there fuses on the light board? I'm not familiar with this era WMS machine. Use a DMM to check the fuses, if its not obvious that one is blown. I would think GI and pop bumper lights are on different strings.

#4 16 days ago

Also, if not already obvious, dont use tools on a game with the game on

#5 16 days ago

Yes, Comet system 9 William. I’m not too smart sometimes. I didn’t see any fuses on the light board? I read the G.I. was controlled thru the power supply board??? I believe these are G.I. lights???

5121589A-95F3-4D73-B4D5-FB59646B5743 (resized).jpegF0314E6D-CF77-402E-A76A-052341A52E18 (resized).jpeg
#6 16 days ago

That's the score display driver board

#7 16 days ago

My bad. The 4 stack of fuses is what the repair manual says to check. I checked all the fuses there and they are all good; plus I have 4.5 volts to both sides of the socket, which tells me the fuses should be good, correct?

#8 16 days ago

3EBCC0E7-6A33-4089-A431-7A355FD735BC (resized).jpeg
#9 16 days ago

84CE65BA-7E8C-4284-90DC-806E4B3BC673 (resized).jpeg
#10 16 days ago

Is this the G.I. relay?

0C714C34-B59F-4B0C-A798-C0F5B72A680C (resized).jpeg
#11 16 days ago

Assuming this relay is for the flasher bulbs only? I swapped it out and it didn’t do anything.

B8B9C92B-5EDD-44E7-ACAA-0B96BDB154FF (resized).jpeg
#12 16 days ago

That connector on the bottom right is burned to shit.

#13 16 days ago

Yeah. It’s been repaired already. Everything works fine, and did before I shorted the bulb socket, except the jet bumper bulbs. Are they on the GI circuit?

AA1BFE54-84D9-4911-9CA6-7C38AF3BD20A (resized).jpeg
#14 16 days ago

The Jets are part of the GI

Follow the wires that chain them together with your meter set on AC volts, and you will find where the break in the action is.

Also, check those GI fuses with your meter, not your eyes. Make sure each one has 7vac on both sides.

#15 16 days ago
Quoted from PinballGurus:

Assuming this relay is for the flasher bulbs only? I swapped it out and it didn’t do anything.

The GI relay does the entire GI when any of the lighting effects occur (like hitting the funhouse saucer)

It's not going to be the relay, it's 99% going to be one of those fuses.

#16 16 days ago

Thank you for your reply. I will try the fuses, etc. and report back. Thanks.

#17 16 days ago

Lesson learned. I originally thought it was a fuse, then talked myself out of it. It was a fuse. Thanks for your help on this. You’re the man!!!

080799C9-58FE-43EF-B14A-03A2F250254C (resized).jpeg994F30C6-B444-47BD-B7EA-38A976A20C58 (resized).jpeg
#18 15 days ago

So now my lights work, but a transistor Q13 has blown on the main board, I changed it out and it blows again; it controls the main gate ramp entrance and probably some other things? I’m assuming somethings been grounded somewgeee causing it? No idea? Has anyone else had this problem?

6F184FF7-8BE5-4781-ACC8-AF9C8297BF08 (resized).jpeg
#19 15 days ago
Quoted from PinballGurus:

So now my lights work, but a transistor Q13 has blown on the main board, I changed it out and it blows again;

Did it ever work since you've had it?

If yes, what what the last thing you were messing with before it blew?

#20 15 days ago

That’s a good question. When I got the machine, the gate wasn’t working, but I noticed it was grounding to a solder repair job that was done to the lights when it was triggered, so I covered that and replaced the Q13 and everything on the machine worked great until I had this light issue; now I’m back to square one. Haha!

What usually causes this? Am I correct to assume I should look for a grounded switch or wire?

The only thing I did prior to this was replace all the old plastics with new.

Thanks for helping me.

#21 15 days ago

Q13 is showing 35 volts while all the others are showing 4.5 volts.

#22 15 days ago

Just checked the voltage on the gate switch and the red/white wire reads 4.6 volts, while the green/purple is reading 34 volts, which is obviously wrong. I’m wondering if my solder job behind the board is causing the issue?

#23 15 days ago

Do those 9 pin network resistors go bad?

#24 15 days ago

Looks like it got fried.

D394F621-7E22-4274-A245-7771CC2F9EB7 (resized).jpeg
#25 15 days ago

The connectors lifted from the board where Q13 transistor connects, but they are still connected. I put in a new transistor and everything seems to check out with the multimeter now. Anything else I can try before I put the board back in?

C249740D-064E-4E0C-89EB-C4A306FDC207 (resized).jpegCA38C6C6-8126-4C0A-BB41-66B9C76527CB (resized).jpeg
#26 15 days ago

Everything is working now. Another lesson learned.

#27 13 days ago

Well, back to the drawing board. Somehow I’m getting 35 volts to the Q13 transistor, which is to the main gate, instead of the 4.5 it’s supposed to get. Today I checked the voltage on the metal gate itself and it too had 35 volts to the gate and I noticed when I lifted the gate up I was getting shocked on the side of the machine??? Any ideas would be appriciated.

#28 13 days ago

Bingo! Found what was wrong. Someone used a larger size nut to bolt down a post and it was touching a metal contact on the drop target. Crazy!

#29 12 days ago


Promoted items from the Pinside Marketplace
$ 22.00
From: $ 16.95
Machine - Wanted
Summerville, SC
450 (Firm)
Sale Pending!
Carlisle, PA
$ 99.99
Playfield - Toys/Add-ons
Lighted Pinball Mods
$ 12.00
Lighting - Led
Bright Lights Pinball
$ 48.00
Cabinet - Other
ModFather Pinball Mods
$ 12.50
$ 18.00
Yorktown Parts and Equip
$ 999.00
Flipper Parts
$ 66.00
Playfield - Toys/Add-ons
$ 399.99
Cabinet - Toppers
Great American Pinball
$ 7.00
Playfield - Toys/Add-ons
ModFather Pinball Mods
£ 79.00
Playfield - Other
$ 79.99
Playfield - Toys/Add-ons
Lighted Pinball Mods
$ 150.00
Playfield - Protection
Republic Of Pinball
From: € 189.00
$ 5,999.00
Pinball Machine
Nitro Pinball Shop
$ 18.99
Matt's Basement Arcade
$ 76.95
Cabinet - Shooter Rods
Super Skill Shot Shop

Hey there! Got a moment?

Great to see you're enjoying Pinside! Did you know Pinside is able to run thanks to donations from our visitors? Please donate to Pinside, support the site and get anext to your username to show for it! Donate to Pinside