Which Universal slot machine is this

[UNIMAN]

Your almost there!

Well, obviously I never played that machine. One just like it and in great shape like that one is.

And, I had the game eprom number wrong. See it is 8729, listed as Triple Progressive Magnificent 7's. And that Game chip is a real money maker with a calculated payback of only 83.207%.

[motofreak6868]

If I start the machine I pay few beer, I'm probably in Vegas around 05.01.2024
It is certainly bad that the device stood for several years in the basement very close to the Adriatic Sea and was exposed to moisture. Continuation of work on Monday. Thanks guys for your help.

[motofreak6868]

Unfortunately, the display soon turned off and doesn't work anymore, so I didn't have time to reset anything. Any advice on where to look for a malfunction?  Can the device work without keys? The lock was removed from the door.

[Pitts256]

Bummer, thought we had it.

Probably have to start from the beginning.

1) Pull the CPU board and check the battery voltage, needs to be above 3.0V. If it's low after installing the new battery then there's a short to ground. Also when the machine is powered up there's a "trickle charger" topping off the battery voltage. The battery needs to be one that can be charged. 
2) Check all the chips on the CPU board to make sure no pins are bent and hanging out of the socket. Also check that the chips are in the correct position and seated in the sockets.
3) Look for any spots on the CPU board that may be shorting due to battery acid corrosion. Repair any open traces.
4) Check the power supply fuses again and the DC outputs. Note: Should the power supply outputs drop there is a low voltage detection circuit on the CPU and it will shut itself down.
5) When you power back up the CPU perform the "ALL RESET" function to clear the RAM and restore default settings.

There is a switch for the door key lock, it may have been removed and the wires twisted together. If there is a switch near the door lock key that could be struck with a lever and the wires are still connected send a photo and we'll determine if it's been bypassed.
 

[UNIMAN]

Yes you can run a machine without the door lock. A few machines had switches, most have a grey optic to verify door is locked. Simply blinding that optic with electrical tape will do. And you can leave it there.

The error 12 says the board is not seeing the battery voltage. Usually a reset on the mpu can bypass this issue til next startup. Yet you lost the display so bigger issue.
The replacement battery must be rechargable Nicd and not lithium.

[motofreak6868]

Unfortunately, there is no progress, does anyone have a schematic for that or a similar device. I'm not even sure if it has all the parts, so I'm posting photos, maybe something is missing. Tnx.

[motofreak6868]

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[motofreak6868]

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[motofreak6868]

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[Pitts256]

Still appears as though you're not getting +5VDC to the CPU and other devices.

That would be the 5amp fuse F3 (9.5VAC to +5VDC)

You can check the voltages at plug CN-4 or CN-7 (see photo).

CN-4 pins
1) +5VDC PINK
2) +24VDC ORANGE
4) +12VDC RED
7) GROUND BLACK
11) +32VDC VIOLET

Check the voltages to ground, pin 7.

Careful...there's 100VAC on 4 of the pins.

PM me your email address and I'll send the manual.

[UNIMAN]

Alright, time to throw some darts and see if one hits.
(Assuming mpu is OK and fuses are OK)

First and most obvious, check your power cord. Cords go threw bottom of machine and are supposed to go into slot stand. Often times sitting on floor the cords can get pinched. Have changed many shorted cords in the past.

Next is the voltage regulator on top of power supply. Once had a similar problem with power and then no power. Voltage regulator has two long leads to a circuit board in power supply. Found a cracked solder joint on one of the leads. Open up power supply and check voltage regulator connections.

Right in front of power supply is that big black connector for wiring to door. Have had pin or pin sockets get pushed down leaving bad connections. Open connector and look at each pin and pin socket for movement.

[motofreak6868]

Thanks for your help, guys, everything that could be checked according to your instructions was done. On the MPU, the Eprom stands were removed and soldered directly. All suspicious parts have been replaced, but the device is still dead. The MPU is going to be checked once again, but I'm afraid it won't work. Tomorrow I will travel to the USA and continue with work after returning to Europe for a one month.
Merry Christmas to everyone on the forum and enjoy the holidays.

[Pitts256]

A quick note before you start back up...

The three units in the top portion of the machine are the Mikon LED display driver boards with power supplies, they appeared to be functioning. I would reinstall all three Mikon units back in the machine for now but leave the power and communication plugs unplugged while troubleshooting the main power supply and CPU board (see photo). They won't be needed until the CPU is up and running.

Also there's a +5VDC voltage regulator inside the main power supply, if you have lost +5VDC at the CN-4 plug and the 5-amp fuse is good then the 7805 regulator has failed.

Happy Holidays!

[motofreak6868]

Hi guys,
Unfortunately, after replacing all the suspect parts on the board, no progress. The slot machine is dead.
If anyone has the Manual, I would be grateful if they could send it to me by e-mail.

irajtic@gmail.com

[Pitts256]

Check your mailbox for the manual.

[motofreak6868]

Thanks Randall, I really appreciate the support and help.