Universal Double Jackpot Wheel Issue – Wheels Won’t Spin / Stuck Trying to Start

[DarrenWarner]

I’m working on a Universal Double Jackpot (early 90s) machine and I’m running into a weird issue I can’t figure out.

🔧 Problem:
Coin acceptor is working normally (coins register fine)
Credits are added correctly
When I press SPIN, the following happens:
I can feel the reels trying to spin / vibrating
I hear the game sound start briefly
Then the sound cuts out suddenly
The reels never fully spin — they just feel like they’re “stuck trying”
The machine stays in this state until I hit the reset button

After resetting, everything goes back to normal until I try spinning again.

⚙️ What it feels like:

It almost seems like:

The machine is getting the spin command
But something is immediately interrupting motor power or the game cycle
The reels are getting power (or partial power), but not enough to fully engage spin
🧪 What I’ve checked so far:
Coin acceptor → working fine, credits are correct
No obvious stuck reels or mechanical blockage
Machine powers on normally
Sounds play briefly on spin press, then stop
❓ Questions:

Has anyone seen this before on Universal machines?

Could this be:

A bad power supply / voltage drop under load
A failing main board / logic board
A motor driver / reel drive issue
Or something like a tilt / safety interrupt circuit triggering mid-spin

Any advice on where to start testing would be really appreciated. I can take meter readings or check specific boards if needed.

[Pitts256]

Hi Darren,

So you have a Universal Ultra.

Typically when there's a stoppage the CPU throws an error code in the WIN METER in the left hand side of the led display. With a normal start-up you'll see a 50/51 or 13 which clears after the first spin. Log any errors before pushing the yellow reset button.

When play freezes do the 4 red LEDs on the frontside of the CPU board continue to strobe right-left-right?

Did you try an ALL CLEAR at startup to clear and reload the program file? If the on board Nimh battery is at low voltage or dead the RAM memory may be corrupt and needs to be cleared.

You can check the voltages on the front left side of the CPU board. The test points should read as follows:
 Yellow to Black  ~  5 vdc
 Red to Green  ~  12 vdc
 Orange to Green  ~ 30 vdc

-Randy