Defender - Self Credits!?

[jetusenet]

Another possible arrow to the problem, sometimes when I press the "start" button, it makes the "start" sounds but remains in "attract". I push the button again and then the game starts.

This had only happened once or twice but may lead to the overall solution to the problem.

If I cannot find a solution by the end of the weekend, I am sending this board-set out!


Jeff

 

[Arcadenut]

Now I'm really upset!

I replaced the PIA on the ROM board, (even though I could not prove it bad) and now it's doing it even more!

Every so often, during initial boot, (cold) I might get a ROM error but then it goes away. This does not happen every time and in fact I had forgotten about it until now as it just happened again, then went away - again. I placed the game in test and of course, all ROMs are good. Could a bad ROM, (intermittently bad) cause this "credit" problem??

This is driving me CRAZY!!!!!!

Jeff

Did you save your original PIA?

If you are having other issues other then just the coin issue, you should take a look at your ribbon cable and look for cold solder joins on the other connectors just to be safe.

 

[jetusenet]

Yes, I always save everything until the problem has been resoved so I can do a review of the autopsy if need be.........
I just booted the game and fired it up, added a few credits, left it for 10 min and came back and it had 99 credits on it.
I shut it down and restarted it, credited 2 games, pushed 2 player and walked away, came back 10 min later and there are zero credits on the game.

Coined 2 more credits, pushed 2 player, walked away and came back 10 min later and there are zero creits on the game.........

I repeated this 10 times and every time I came back, there were ZERO credits on the game.

I coined 3 credits, pressed 2 player, walked away, came back and there was one credit but now when I went to add a credit, I received 5 credits for one flick of the left coin switch! It then started self crediting again......

Could something be happening when I credit more than 2 credits or if a credit is left on the game???

Why did the left coin switch, which is programmed for one credit per coin, give 5 credits when it was energized??! BTW, it added arbitrary amounts of credits and now just adds one per flick......

I went back into test and the center coin switch is being energized very quickly, like a short. I am going to film it and post it but of couse, the camera was left on the counter with a dead battery so I have to charge it before I can use it - Ah, married life.

One other thing, when I pressed the center diag switch, "switch up", the display erased the "switch Down" and the center switch stopped flickering. When "switch down" was dispressed again, the center credit stated to flicker again and this goes on and on. BUT, it is not the physical switch as I disconnect the coin door and the center switch remains lit!

I'll post the video once the camera is charged.

Jeff

 

[jetusenet]

Does anyone have a JROK board for sale??

 

[kstillin]

What is the supply voltage to the PIA? Any ripple there? Slightly low?

Do you have a center coin switch connected at all, or are the wires just hanging?

Bad switch? Debouncing capacitor bad? (multiple hits registering)

I found somebody that will sell working Williams boards for $65 with trade-in of yours. More economical than some other options...

Kerry

 

[jetusenet]

I was thinking that as well. I am going to pull the CPU and Widget and cap those and see what the results are.

BTW, I have the original P/S installed AND a switcher as well and this problem occurs no matter which power supply is used!

Jeff

 

[jetusenet]

OK, here is the video:

http://www.youtube.com/watch?v=XjowT0JVTY4

You can see that when the center diag buton is depressed, the problem stops. Then pressed again and the center coin becomes energized again.

There is no center coin present in the coin door. All wires have been exposed and nothing is shorted. If I disconnect the coin door, the center coin switch REMAINS lit so the problem is board related.

Is the Widget involved in the coin up process at all or is it just the ROM board involved??

Jeff

 

[YellowDog]

It is just the ROM board that is connected to the coin switches. That almost sounds like one of the 4049s in front of the PIA on the ROM card is going bad or there is an intermittent short in the ground line to the coin door.

The Up/Down switch only registers in the down position. So that is why you only see it on the switch test screen when it is down.

ken

 

[jetusenet]

It is just the ROM board that is connected to the coin switches. That almost sounds like one of the 4049s in front of the PIA on the ROM card is going bad or there is an intermittent short in the ground line to the coin door.

The Up/Down switch only registers in the down position. So that is why you only see it on the switch test screen when it is down.

ken

Ken;
I probed the 4049 during this situation, for the right, the left and the center coin and NONE of the inputs or outputs changed state during the situation. I tested the right coin while actuating the microswitch and did register state change on both the input and output of the 4049.

I unplug the coin door while the situation is occurring and it keeps on going. Also in the switch test screen, when the center is constantly lit, I unplug the coin door and the "down switch position" indication extinguishes but the "center switch" remains lit so I really do not think the coin door is involved, it is after that somewhere.

It is after the PIA, how do I check for that??!!?

Thanks
Jeff

 

[jetusenet]

This is a good one!

I pulled the widget and CPU PCBs, re-flowed all connectors, checked for failed components and capped them both, I already had totally rebuilt the sound board and capped and replaced the PIA on the ROM PCB. I even replaced the 4049 on the ROM PCB as I am now second guessing myself!
I fired it up and......... %$#@ self crediting!

I was really pissed and started tugging on connectors in the switch test and came to the widget ribbon cable and when I pulled that one, I could hear the center coin switch going on and off! I had already re-flowed the connectors so it wasn't that and in a fit of RAGE I gave the ribbon cable a good stiff pull from the widget PCB and it stopped! No more self crediting! Even the question mark that was the first character of the high score was now replaced by a numeral. Brute force - YES!!

Now I am wondering why the widget PCB had ANYTHING to do with the center credit switch when the schems show the circuit going through the ROM PCB.....

But I have to remember that the credit situation was occurring even though there was no state change on the 4049 so that means that this was caused by something AFTER the ROM PCB - where does the signal go after it leaves the ROM PCB, the WIDGET!?!?

Can anyone explain why when I pulled the cable from the widget PCB the center credit switch stopped giving credits???

I have been playing this game for the last 2 + hours and it works perfectly, no extra credits, no question marks in the HS table, just a 100% functioning Defender game........

I guess the widget is more involved in the big picture than I had originally believed!

Good night!
Jeff

 

[Arcadenut]

This is a good one!

I pulled the widget and CPU PCBs, re-flowed all connectors, checked for failed components and capped them both, I already had totally rebuilt the sound board and capped and replaced the PIA on the ROM PCB. I even replaced the 4049 on the ROM PCB as I am now second guessing myself!
I fired it up and......... %$#@ self crediting!

I was really pissed and started tugging on connectors in the switch test and came to the widget ribbon cable and when I pulled that one, I could hear the center coin switch going on and off! I had already re-flowed the connectors so it wasn't that and in a fit of RAGE I gave the ribbon cable a good stiff pull from the widget PCB and it stopped! No more self crediting! Even the question mark that was the first character of the high score was now replaced by a numeral. Brute force - YES!!

Now I am wondering why the widget PCB had ANYTHING to do with the center credit switch when the schems show the circuit going through the ROM PCB.....

But I have to remember that the credit situation was occurring even though there was no state change on the 4049 so that means that this was caused by something AFTER the ROM PCB - where does the signal go after it leaves the ROM PCB, the WIDGET!?!?

Can anyone explain why when I pulled the cable from the widget PCB the center credit switch stopped giving credits???

I have been playing this game for the last 2 + hours and it works perfectly, no extra credits, no question marks in the HS table, just a 100% functioning Defender game........

I guess the widget is more involved in the big picture than I had originally believed!

Good night!
Jeff

Glad to see you got it working. I would check that ribbon cable and make sure it's tightened down. When you pulled on it, it might have made contact with a wire (maybe ground?) and the connector on the board.

You may want to consider replacing that ribbon cable too.

 

[jetusenet]

I am going to order the replacement ribbon cable but I still would like to know why the Widget has the effect it does on the center coin switch!

BTW, it's still working perfectly......

Thanks everyone for you support and help through these trying times.

Jeff