S2000 project in progress

[Stayouttadabunker]

The problem with cleaning the MPU board it is that it's usually already too late.
Often, the battery acid is now under the protective covering, and eating the copper traces alive.
All you are doing is cleaning the surface.

[t28c34]

Yea I see a little bubble. Would I be able to open it up and clean it out? It looks like it is not into one of the lines yet. I need to pull the board back out to solder in a CR2032 battery holder anyway. I just have it rigged right now to be able to troubleshoot. I did use just contact cleaner around the area of the Varta battery both to top and bottom, but since I have to pull it back out Ill scrub it with vinegar also.

[Stayouttadabunker]

You will need a multimeter to check for circuit trace continuity from one end to the other at various points on the MPU.
A "bubbled" trace means there is a chemical reaction going on UNDER the conformal coating - that's not favorable to your MPU's lifetime expectancy.
Many of these MPU's are hitting 20+ years old now?
If you look at this link, you can read that there are several different kinds as well...>>>
https://www.masterbond.com/industries/conformal-coatings?

In reality, the only way to save the board at this point in time is to remove all the damaged trace coating you can find, clean, and re-cover them.
As far as I know, only member Lookes is experienced with that...I'd contact him.
You're required to have the correct equipment to deal with tiny, microscopic circuit trace repairs.
Good luck!
 

[Brada]

I had a 502 board in my box of spare parts. I swapped the game chips over from the 504 into the 502 and put it in the machine. After the ram error popped up and got that reset, machine acts exactly the same. Door closure MB and coin-in jam errors. Booted machine up with door I/O unplugged and machine comes up to same errors. With the door I/O plugged in there are no leds lit on the board. I’ve followed the wiring down to the backplane and checked all connections. Multimeter shows 13v and 25v on red and orange wires respectively. Leaning towards a bad I/O board. I’ve read there’s multiple different boards that look identical but are different.

How does one know what the proper I/O board is for this machine? Want to make sure a wrong one wasn’t installed in the past before I got machine. The one currently installed is a board pn 75427802. Ready to order a replacement to try but want to make sure this is the proper one?

[Stayouttadabunker]

Swap the six chips marked in yellow onto your other MPU, one chip at a time, in the same direction (very important).
Make sure all the chip legs are fully inserted down into each socket hole, and none get folded underneath the chip's body.
Then swap the large multimedia audio sound board.

If your other MPU has the green Varta battery, remove it by cutting the legs about one 1/16" above the surface.
Do NOT scratch the circuit board with the sharp pliers.
You don't want the small circuit traces near the legs of the battery to get cut or ripped off the circuit board.

[Brada]

Update

After swapping boards there was no change. Talked to Lookes and he is leaning towards a bad door I/O board. I was told earlier that my buttons should light up. I did find they had bad bulbs, but when I replaced a bulb it still did not light. Testing in the bulb socket of the play 2 credits button I am measuring 13 volts. Bulb continuity is good. Head scratcher. I put my multimeter leads on the bulb contacts, and as soon as I touch the bulb to the leads the voltage drops to 0. Could this be bad power supply? Seems as soon as the load of the light bulb hit the circuit the voltage dropped out. Seems crazy!

Where does the 13v for the switch bulbs come from? What boards does it travel through between the power supply and the buttons?

[Stayouttadabunker]

You may need to check the bulbs in your button deck.
Ideally, there's only supposed to be one contact per side on a wedge bulb.
If you put in a wedge bulb that has the wire leads coming out on both sides of the bulb, esp. certain LEDs, they short out the socket and jam up the logic....essentially freezing up the system rendering the button deck dead, or worse.

[Brada]

Getting so close!!  Thank you for everyone’s help so far, Jim at Midwest Slots hooked me up with a different door I/O board and that took care of the coin in jam error. He also got me a cash can as I was missing one. After going through settings and re-enabling the bill validator everything appeared to be working! I put in a $100 bill and I had credits on the machine. Bet max a couple times and the reels spun and all was well. Tried hitting bet 1 twice and pulling handle and it went into a reel tilt. All the reels have a hum to them and just continue to spin slowly. Tried cycling power and after reboot they go into their noisy slow spin. Any ideas?

[Brada]

Getting so close!!  Thank you for everyone’s help so far, Jim at Midwest Slots hooked me up with a different door I/O board and that took care of the coin in jam error. He also got me a cash can as I was missing one. After going through settings and re-enabling the bill validator everything appeared to be working! I put in a $100 bill and I had credits on the machine. Bet max a couple times and the reels spun and all was well. Tried hitting bet 1 twice and pulling handle and it went into a reel tilt. All the reels have a hum to them and just continue to spin slowly. Tried cycling power and after reboot they go into their noisy slow spin. Any ideas?

After doing some reading I used the jackpot key to reset the reel tilt and it’s working again. I think I must have had the door latch not quite closed and it was a door optic issue.

I still have no sound though, so I will start researching that. If you e got any suggestions I’m open ears!

[idesign]

Brad, I can't respond to you messages, empty your mail box.