I programmed my own testroms for those Bally 2518 CPU boards and also used S33 to start a socket test. S33 is connected to the CPU /NMI line; an NMI routine will be started after pressing this switch. The /NMI vector (or start address of the /NMI routine) is located at $FFFC and $FFFD ($7FC and $7FD in 2kB ROM, $FFC and $FFD in 4kB ROM), HSB - LSB. In this routine you could add an INC <address creditcounter> if there is space and after you resolved the address where the creditcounter is stored in RAM. And correct the checksum data when you're done. Is this an answer to your question or did I misunderstand?

Marco

Marco -
That's perfect, thanks! I have the credit address already, so just need to increment one to that register - *IF* we're not in test mode. (Checksum is already disabled; dangerous, but, easier for testing..!)

If it's not cold solder joints on the display board I would replace the chip.

I have a NGS with full LEDs. No flicker and have alltek light board. Every once in awhile the outlane switches cause all computer controlled lights to flash continuously . It looks just like light test mode from coin door switch. As soon as another switch is hit all lights go back to normal. Any ideas?

I have a working mpu out of the NGS . Battery was removed and no damage. Also have untested light board and metal cash box. PM me if need any of those parts.

Got an odd problem on my kings of steel. Left flipper died on me. Right flipper still works fine. Checked the EOS switches and they are good. The wires on the flipper coils werent soldered very good so I cleaned that up too. Still no left flipper.

Any suggestions? I'll pull out the DMM if I need to.

Meter the coil to make sure it's not dead.

Check continuity between the flipper coil and the SDB.

Repin the SDB.

You seem to be familiar with these games. Any ideas for my lighting issue listed above? I started a separate thread but non one has responded. Thanks.

Hello, I have a Flash Gordon and a Supersonic. Does the SS fall into this group? Both machines are completely dismantled I bought a CPR playfield for the FG about three years ago. The machines have been sitting since then. Went through an employment change and big move. Just now getting back into the game. This looks like a great forum.
Thanks,
Brad

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Voltages all read fine. Swapped over to ohms, I believe this indicates a failure. Right?
Clipped the diode just to be sure. (Edit: I was getting .01 ohms before I clipped the diode)

The middle and right lugs gave me a 3.0 ohms reading just like the other two flipper coils.

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Curious about your progress in this Pressing the button will generate an Non Maskable Interrupt. Normal behaviour of this button is to clear the selected bookkeeping data, or high score, or setting. I never disassembled the Bally code but I would expect it is just a CLR <address>, Indexed by the selected step in testmode. Even if you are not in testmode, there will something happen, maybe an unused address will be cleared.

Working with /NMI routines at those Bally boards and also some other boards learned me why Williams designed a nice "Glitch generator" with 2 Nand ports. When you press the testbutton a long time, a lot of NMI's will be handled.....

Marco

By this chart you should see around 3 ohms on those coils.. https://www.flippers.com/coil-resistance.html

If the coil is good, start working your way back towards the SDB.

Um, no... But I would start by checking those outlane switches for shorts. Especially where the play field rests on the case supports.

Your are reading 0.285kOhms, 285 Ohms. This could be normal for the Hold winding (4500 turns 34 gauge) from the flipper coil. You can compare it with the other coils (open the EOS connected to the flipper coil).

Thanks for the reply. I'll check.

Got my new speaker and it sounds fine. Speaker was gone when I got it so I put a bookshelf speaker in for awhile temporarily. Anywhew, mounting it up earlier and noticed the ground right next to it not connected? Does this mount under one of the speakers screws? Feel dumb for not knowing. And, had one bulb I could not get to work so I soldered in a new socket and still nothing? I know it worked off and on for awhile, but no more and the new socket and bulb, still nothing. It's the #10 insert for the horseshoe targets. Stumped on that one.

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Bingo.

If the bulb is not flashing during the lamp test, jump the wired tab to the wired tab of the working bulb next to it. It it lights, the problem is not the bulb or socket. It will be either one side of the plug into the light board or the transistor that controls the light.

in case you are interested

https://pinside.com/pinball/forum/topic/why-not-a-viking-restoration#post-3549006

So, I'm just running a wire from one connected socket (dead one ) to the next working one correct?

Yes. This is just a test, use an alligator clip. If the light lights, it's not the socket.

Do you have a diode installed on that new socket? I doesn't look like if from the picture.

I had several bulbs not working on my Baby Pac that I swore were bad sockets. Ended up being blown whimpy SCRs in the lamp matrix.

Is this the ONLY controlled lamp this isn't working? When the SCRs blow, the bulbs stop working in pairs. You should be able to tell if it is a bad SCR by looking at the schematics for your game and checking if the other bulb paired with this one is not working as well.

No, no diode installed. And it is the only controlled lamp not working. Guess I need to install I diode or get a lamp socket with one installed. What about the ground near the speaker?

Looks like the wire Yellow/ green has come off the solder tab? , Could even be a bad solder joint on the common wire ,right next to the bulb holder mounting screw( Check that using a screwdriver shorting the solder blob to the Common)
It that fails
Trace that wire colour to the lamp board connector , gently pull on the wire right at where it goes into the connector , if it lights up , the connector could need re soldering , or replacing .or even a new crimp on that wire.
If no luck trying all that ,
the Transistor or SCR that drives the lamp must be blown.
Speaker , yes mount the earth strap under one of the speaker screws.
Good luck

The wire is currently not soldered on. I desoldered it and tried a different socket. Is a diode needed? Where the socket mounts to the PF, it is soldered to the common wire.

Oh got you now about the loose wire , And if your sure the common has a good connection.
try looking at the connector pins on lamp board for cracks. If connectors are good , it must 95% sure it would be the SCR or transistor for that lamp
Diodes , The other sockets dont look like they have any on them , So the new socket won't need one either .
By the way what game is this EBD?

I'll double check the common connection. Redid it at least twice to make sure already, but maybe i'll redo it again. And yes, it's a EBD

That common should be okay , if you have re done it ,
What lamp is not working?? , I have the manual here and can work out which transistor it is for you
Probably one of the smaller 5060's on the Lamp board, but this game also uses a 2nd aux lamp board to, but all those on the aux are of the bigger MCR-1060 type.
So if you can tell us which lamp it is exactly, ie 10 Target, "d" , 7 Rack etc...???

It's the "10" insert lamp for the drops. Next to the 1-7

The '10' insert lamp , driven by Q26. which is a 2N5060.
Manual list that lamp as the '10 Target' and colours yellow/green so it must be the right one .
The connector pin is J1 pin 7 on the main Lamp board
good luck mate ...

Are there any owners/users here of the Rottendog BPS054 rectifier board in their 80's Bally game? Any issues with the board, would you highly recommend it?

Thanks, appreciate it. Will save me some time in the manual later. Hope to get back to it tonight..

Look closely at the original socket. The mounting bracket is soldered to the common wire and there usually is a diode built into the socket between the mounting bracket and the contact point for the bulb in the socket. It is on the back side of the original socket in the picture you posted. I do not have an EBD but that is the way the sockets are on my Baby Pac.

Will do, thanks

I just installed one a few days ago in my Silverball Mania. I have not had any issues. Just make sure to check the installed fuses as the Rottendog schematic lists slo blo in spots that the machine's manual lists as fast blo.

I don't know when they started adding diodes to the lamps, but none of Mystic, Rolling Stones, HGT had diodes on the sockets. If all your other sockets don't have a diode, then this one probably shouldn't either.

No experience with the Rotten Dog, but the Great Plains board has been great for me. I've used 2 of those.

Here's the original 555 socket. Don't see a diode. Hopefully tonight I can do some digging.

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Jumped the new socket in test mode, it works. So that definitely narrows it down.

See the slot in the plastic at the top as you are holding it in the picture? There is another terminal in that slot on the working sockets. From the terminal in that slot, there is a diode that connects to the mounting leg. The diode may get routed under the bend in the mounting leg (to the right in your picture). The diodes on my sockets are the small, pink glass type, not the black plastic type common on other games and modern games.

That is the way my sockets are laid out. But as aobrien points out, your sockets may be different than the ones used on my game.

But if it works when I jumped it to the adjacent socket, it must me something else I assume?

Yea, now that I think about it, if the Diode was missing, I think the bulb would be lit all the time. It wouldn't hurt to take a close look at the working sockets and confirm there isn't a diode on them.

If there are no diodes on the other sockets, it's most likely the SCR on the board for that lamp.

Yes, it's something else. And the ground by your speaker wire goes under one of the speaker mounting screws. Helps with any potential feedback and such.

No need for a diode. Only if you install led bulbs. As Ralph67 mentioned, the wire for that bulb is yellow with a green chaser that meets the light board at J1 pin 7. Check the wire, check the plug and check Q-26. One of those is your problem.

Appreciate all the input guys, I really do. I hope to get into more tonight or this weekend. Unfortunately I have another issue I'd rather address 1st. Wanted to get the entire underside done (new targets, this and that etc) done so I could flip the PF back into place and finish what's left on top. Well now when I start a game it gives me the 7 Ball right away. Target doesn't drop, just gives me credit for it. Dive into that 1st, since now I have to prop the PF straight up again for easier access.

Make sure the switch isn't stuck closed.
Replace the small cap across the switch tabs if it has one (can snip one leg for now if you don't have e a replacement on hand)
Replace the diode on the switch if it has one
Could be another board transistor problem

The 7 ball switch is now working. The leaf switch was closed. Re gapped it, it's fine now. Checked the pin on J1, seems fine as does the connector and the wire connection. Assuming it's Q26 is the problem. No way to test it.

Double post, sorry

You don't have a multimeter?

Nope

Respectfully, It's a "Must Have" tool Sir.

No issues there . I have a buddy who is going to lens me an entire new board set. Very frustrating problem.

Yeah, you should pick one up. Can get a cheap one for $10 and a decent one for $20.