universal slot machine jam

[Pitts256]

How about the door key lock switch?

There should be about +32 volts DC on the the two wires to the coin comparitor. Orange the positive to green the ground. The green LED on the front of the comparitor should be on when there's power at the plug. Unplug the connector from the comparator and inspect for any signs of hot spots, burns, like an overload.

 

[bidault]

The power is on and there is no voltage on the wires to the coin comparator. the green led is not lit. The connector is perfectly clean.

[Pitts256]

So there should be power to the coin comparator when the power supply is powered up. Check for voltage at the power supply plug CN-4 (see photo). The +32v DC is measured from the black wire (pin 10  ground) to the violet wire (pin 11  +32v). No voltage? Check the 3 amp fuse F6. There's voltage at the CN-4 plug wires? Then check the white plug just to the right side of the coin comparator for +32v, follow the plug-wire from the comparator red plug around the backside to the white plug, should be a violet and black wire. Let me know what you find.


Still need to know too if the door key lock is making or breaking the photo eye as mentioned earlier. Is there a lever on the key lock that makes or breaks the photo eye beam? Is the red LED going off-on? In your photo the LED is on.

[bidault]

Sorry for the delay I was travelling abroad. I checked the voltage  at the power supply plug CN-4 it's OK 34V. I checked the white plug on the right side of the coin comparator following the wires from the red keyplug, no voltage betwin the blue and violet wires (picture). There is a lever breaking the photo eye on the the key lock system of the door (picture)

[Pitts256]

Welcome back!

First lets test the key lock lever. When you turn the key the lever should block the switch photo eye and the LED light should go out. If it does we're good, if not try blocking with a piece of paper. If it's still on the switch is bad.

Next we need to find the 32vdc to the coin comparator. Yep, the violet & blue wires should have 32vdc but only when the machine is ready to run. On the CN-10 9 pin plug (see photo) check for 32vdc between pin 7 (violet) and pin 8 (black). If the CN39 pigtail is there it's easier to check for voltage at the pigtail. The black wire and violet wire should have 32vdc. The blue wire is the comparator inhibit control wire. So if we have 32vdc between the violet and black wires then I still think there's a permissive holding us out.

Also take a look at the backside of the white cherry switch, the wires need to be connected the same as the ones in the attached photo.

[bidault]

The key lock lever works properly it in and out the switch photo eye when the key is turned. The red light goes on and out. I found32vdc on the CN-10 9 pin plug between the violet and black wire (7and . The cherry switch are connected properly . I tested the switch and it works.

[Pitts256]

So with the door open lock the key switch, the lever blocks the photo eye and the LED goes out.

Then pull the cherry switch out to the detent position.

Does the green light come on for the coin comparitor?

[bidault]

the door led out and the cherry pushed the green light is still out. At any time when I switch off the general power 12 is again visible in the win meter and I have to reset the main card to make it disapear.

[Pitts256]

When there's an error code 12 you have to powerup the machine while holding the CPU Board "ALL CLEAR" button for about 2-3 seconds. The coin deflector chute solenoid (just below the comparator) should pull in indicating the CPU has loaded the system program and is running. The fact that ERROR 12 is returning means there's a problem with the CPU Board battery circuit for the HM6116L RAM chip. Could be the battery voltage is below 2.8 volts, the battery switching diode D5 is bad or there's no 5vdc to the RAM chip...switching diode D4 could be bad.

Error code 12 could also be telling us that there's a RAM ERROR. Could be a bad ground somewhere in the cabinet, the 5vdc is shorted to ground or there's a defective component on the main board.

My ERROR CODE 12 experience has always been a bad battery or a defective "charging" circuit and in most cases clearing the error at startup didn't prevent the machine from running. At this point I'd do a thorough check on the circuit checking for an open trace or bad component and assuring that we have 5vdc to pin 24 of the 6116 RAM chip from the battery (power off) and VCC (+5vdc - power on).

I'll keep looking for a logical reason why you can't get a run permissive.





   

[bidault]

I am not an electronic specialist nevertheless the battery voltage is 3.8V and the diode D5 is bad. the diode D4 is good. To help me to check can you show me where is the 6116 ram and if there is specific points I must control. Can you tell me the specifictions for the diode D to buy a new one.

[Pitts256]

The two diodes D4 & D5 are silicon switching diodes, number 1S1588. They can be found on eBay but obsoleted at most electronics suppliers. An acceptable alternative is the 1N4148.

As far as checking the continuity of all the circuit traces, doing so will test your patience. Each one of the traces from the CPU (Z80) to the Eproms and RAM all have to be rung out. Yesterday I started working on the same board you have with similar symptoms and so far have found three open traces on the bottom side of the board, just below the battery. Appear to be from a combination of weak solder joints, battery acid, heat and old age. The solder joints have been repaired and the board now boots to the Error 12, same as yours. The Eproms and RAM tested good, battery circuit's good so I suspect there's a problem with the memory decoder chip (74LS139) or related chips as the system rom is loading but the game rom is not. I'll keep you posted on what I find.

So although replacing the switching diode may alleviate one problem there still may be an issue with the ROM or RAM loading. Try the diode first to see if that restores play.  PM me your email address and I'll send the information to check the traces.

[bidault]

sorry for the silence. I found the exact diode and I changed it. Putting the board in the machine 12 is still on the sceen; I reseted the main board and 12 disapeared but came again if i turn off the machine. Once resetting the baord the machine gave a a sound of play I was so surprised that I pull out my hand from the board. But it did only once. I am desperate with this trouble. What surprise me is that sometimes something occures without any visible matter. If I will not be able to repare this board with your help is ther any possibility to buy an other one or find someone able to repare this board.
 

[Chris-socal]

I don't want to derail your conversation, I know you are working toward getting the machine to boot.

I cannot resist saying that you must get that green corrosion under control. You need to lift that top board too and make sure the green hasn't traveled and started consuming other traces underneath. When batteries leak, the corrosion can travel several inches along traces. It gets under IC's and can eat legs off of components. 
Many people go directly to vinegar but I start with a light wash of baking soda and water, that neutralizes a lot of the corrosion. It is safe to brush it under the IC's and such too. You can use a wash of vinegar and water too but remember that is acidic so you need to be sure you flush it well when done. You can finalize with a wash of distilled water and/or isopropyl 90. You might have to brush and scrub to get the corrosion off but you must do it.
After you get it all cleaned use a multi-meter to verify all traces still work. If any are broken run jumpers.

I was working on a board that had damage from a leaked battery and when I was checking components a diode popped right off because the leads were corroded to a powder state. Don't trust a visual inspection if the legs had green on them.

I know I make it sound like a horror movie but acid damage kills!

Chris

[Pitts256]

Chris is dead on. The traces must be thoroughly cleaned and then rung out to the schematic to make sure there are no open or shorted circuits. As I stated earlier I'm having the same issue with an 8116 board. At least after fixing the open board traces the machine doesn't sound like a pinball machine in play while powered up. I haven't ordered the replacement logic chips yet.

Finding a a replacement main board in working condition is extremely rare. You might post in the want ads on the NLG website. Check for a shop that repairs slot or pinball machines in your area, they may be able to help too.

[Pitts256]

RECAP/UPDATE:

So here's where I ended up with this Universal Star's & Stripes with an 8116 board.

-When I first looked at the machine, the seller plugged it in and it sounded like a box of bolts being dumped into a metal trash can. Wasn't beat up so I bought it anyway and I needed some more Universal experience.
-When I got back to the shop I pulled the CPU board and found a leaking battery, corrosion wasn't too bad though, the board looked repairable.
-I cleaned the board up first and dried it out.
-There were several issues in need of repair...traces, eyelets, an Eprom socket and a flakey memory decoder chip.
-Repaired each of the issues, installed a new battery, installed the CPU board in the machine and powered up. The display came up with an Error 12 (Battery Polarity). The battery voltage checked okay to the RAM.
-Suspected a RAM or ROM issue. Swapped out the 6116 ram chip, same error. Replaced the GAME rom, same issue. Replaced the SYSTEM rom, the machine fired up and with the exception of no sound is up and running like new. The SYSTEM rom was corrupt.

I'll work on the sound and post another topic. UPDATE: The no sound issue was an easy fix, the SOUND rom was in the wrong socket.