Tekken PCB damage?

[Flip_Willie]

  A while back I converted a working Tekken 2 machine into a Mame cabinet.  That worked out great; however, now that I have another Mame cabinet, I was thinking of putting the Tekken PCB back into my first cabinet.

  Anyway, there is some damage on the PCB contacts, and I was wondering if it is okay to put back into the cabinet.  I do remember that the coin lights stopped working after a while when I still had Tekken in the cabinet, but other than that, the game worked great.

   Pardon my ignorance on the matter -- I know almost nothing when it comes to PCBs.

   Thanks in advance!

Just as it is,
Flip Willie

[tommy]

The board is probably dead or something about the board is not working properly after it was fried. I don't think plugging a bad board into a cab setup will hurt any other part of the cab if that's what you're asking.

[Flip_Willie]

The board is probably dead or something about the board is not working properly after it was fried.

  Um.... As far as I know, the board works fine (I hope it still does anyway).  It worked perfectly right before I took it out of the cabinet (Except for the coin lights, which stopped working).  Only when I took it out of the cabinet did I notice the damage.

I don't think plugging a bad board into a cab setup will hurt any other part of the cab if that's what you're asking.

    Yeah, that is what I wanted to know, thanks.


Just as it is,
Flip Willie


 

[D_Zoot]

That would be the +5vdc feed terminals for the board.   The coin lights were probably daisy chained off one of the pins.

While the board may have worked, it isn't going to for long.  Once those terminals finish burning up and the +5vdc starts to drop due to high resistance or open connections, the board will quit working.

I'd repair that before the edge connector get's burned any worse than it is now.



D

[Flip_Willie]

That would be the +5vdc feed terminals for the board.   The coin lights were probably daisy chained off one of the pins.

While the board may have worked, it isn't going to for long.  Once those terminals finish burning up and the +5vdc starts to drop due to high resistance or open connections, the board will quit working.

I'd repair that before the edge connector get's burned any worse than it is now.



D

   Thanks D_Zoot, I was sort of thinking that it had something to do with the power to the coin lights. 

   Exactly how should I repair the edge connector?  (I am sorry if that is a dumb question)

  Thanks a lot!

Just as it is,
Flip Willie

[knave]

Wouldn't it also be a good idea to test the voltage of the power supply. Arn't they ajustable? If so It might be crankes up and that might explain the burning.

Also arn't the coin lamps etc. usually 12v?

I wouldn't begin to know how to repair the edge connector but you could get a fingerboard and solder/connect from there...Not sure what good it'll do if there is something getting that hot though, I'd worry about that.  Hopefully it is a bad splice which you can eliminate.

[Lutus]

Determine if the lights are +5V or +12V and you should be able to tap into the right voltage somewhere else on the board or power supply.

[D_Zoot]

Wouldn't it also be a good idea to test the voltage of the power supply. Arn't they ajustable? If so It might be crankes up and that might explain the burning.

High or excessive voltage does not cause burnt edge connectors.   Poor terminal contact due to loose fitting terminals or tarnished contacts create resistance.  Current flow across resistance generates heat.  This heat burns the edge connector.   So no, voltage is not the an issue here.


There are a couple of different methods to repair an edge connector.   If this board is going to be in a typical Jamma rig where you might be swapping boards out on occasion,  and need to unplug and reconnect the board from time to time, I'd highly suggest one of the fingerboard methods.  Anything else (such as foil repairs) won't hold up long to repeated unplugging and plugging back in.

Bob Roberts has a nice writeup about one way to do a fingerboard,  plus he stocks the parts to do it:
Read here:   http://www.therealbobroberts.net/pace.html


Don't forget to replace the terminals in the harness connector when you repair the board, they are likely as damaged as your board edge!


Also, like Lutus mentioned, it's not a bad idea to trace the coin door light feed and see if it is daisy chained to the Jamma connector.  It's not uncommon to find them wired like that.    In cases like this I will often move the coin door light feed right to the switching power supply,  either +5 or +12, depending on which bulbs you have or want to use (like 555 will use +5 and 194's use +12).  It's not something you need to do if you have good connections, but that current, small amount that it is, doesn't need to be on the Jamma connector, so moving it right to the switcher will lighten the load on the edge connector a little.


D

[northerngames]

looking at the picture of the pins more then likely it was the the light that did that and they flickered as they were dieing becuase the contact was started to ark and thin out.

I would put an inline fuse on the lights next time just to be sure that they dont short anything out.

also by looking at the picture the 2 trace's run on the same path and they run to a via on each and on the other side it has the exact same traces in the same spots so all 4 of them pins 2 on each side are all running the same volt.

that would explain why the game still works but the lights dont the lights died becuase there is no more metal contacting them but the game worked becuase it still has the needed pins for it to work intact still.

the next pin next to the burnt one is just a key pin it has no trace's and does nothing so it is not a concern.

I would just wire the lights with a inline fuse off something else and clean up them pins a little to get the black burnt crud off them and perhaps put a little flux past on them wipe it off and it should be good to go again.

[Flip_Willie]

looking at the picture of the pins more then likely it was the the light that did that and they flickered as they were dieing becuase the contact was started to ark and thin out.

I would put and inline fuse on the light's next time just to be sure that they dont short anything out.

also by looking at the picture the 2 trace's run on the same path and they run to a via on each and on the other side it has the exact same traces in the same spots so all 4 of them pins 2 on each side are all running the same volt.

that would explain why the game still works but the lights dont the lights died becuase there is no more metal contacting them but the game worked becuase it still has the needed pins for it to work intact still.

the next pin next to the burnt one is just a key pin it has no trace's and does nothing so it is not a concern.

I would just wire the lights with a inline fuse off something else and clean up them pins a little to get the black burnt crud off them and perhaps put a little flux past on them wipe it off and it should be good to go again.

   Wow, that sounds pretty easy.  (I love easy things)     I would try to do the fingerboard thing, but I would probably just mess it up trying.

   So, technically, I could just clean up the board and disconnect the coin lights and I would be fine?  The coin lights don't matter a whole lot to me actually.  I just want to play the game.   

  I don't mean to sound lazy, but I am lazy.

  Thanks to everyone for their input!

  EDIT: If I actually need to go ahead and do a full repair, then correct me.  D_Zoot mention that it wouldn't have been a voltage issue.

Just as it is,
Flip Willie
 

[northerngames]

you might want to check the female end that it plugs into to insure it is not cooked either.

[D_Zoot]

Scraping the black off burnt connectors and slobbering some flux on them isn't going to "fix" cooked terminals.  Yes, you will probably get it working, for now, but the connection will be less than ideal and it is not a long term fix.

Let's assume that the "repaired" connection still has 1 ohm of resistance due to reduction in the mating sufaces and tarnishing.   Let's assume that the board requires 5 amps on the 5 volt line.  5 amps across your compromised edge connector with 1 ohm of resistance (P = I2 * R) will give you a power dissipation of 25 watts at the edge connector.  25 watts is 85 BTU's per hour of heat in the edge connector.   As heat build up in the connector, resistance increases, which in turn increases the dissipated wattage and heat.   This is how your edge connector got burnt in the first place.


It's about current and resistance, not voltage,  all basic ohm's law stuff.  These are the fundamental principal's of electricity and electronics.  

I don't mean to come off like a jerk,  but I cringe when half-assed repair methods are suggested to those just learning how these things work.


I'll shut up now......      



D



  

[Flip_Willie]

Lol.

Clean off the edge connector, plug the board back in, and have fun playing it.

Or spend hours 'repairing' your harness and wiring because "something" MIGHT happen to your $15 JAMMA board.

  Oh, come on -- it is at least worth $30.   

Scraping the black off burnt connectors and slobbering some flux on them isn't going to "fix" cooked terminals.  Yes, you will probably get it working, for now, but the connection will be less than ideal and it is not a long term fix.

Let's assume that the "repaired" connection still has 1 ohm of resistance due to reduction in the mating sufaces and tarnishing.   Let's assume that the board requires 5 amps on the 5 volt line.  5 amps across your compromised edge connector with 1 ohm of resistance (P = I2 * R) will give you a power dissipation of 25 watts at the edge connector.  25 watts is 85 BTU's per hour of heat in the edge connector.   As heat build up in the connector, resistance increases, which in turn increases the dissipated wattage and heat.   This is how your edge connector got burnt in the first place.


It's about current and resistance, not voltage,  all basic ohm's law stuff.  These are the fundamental principal's of electricity and electronics. 

I don't mean to come off like a jerk,  but I cringe when half-assed repair methods are suggested to those just learning how these things work.


I'll shut up now......     



D

   So, if I play the game for 30 minute increments with 1 hour cool down time, I will be fine?  (JK)

   In short, if I want to keep the game working, I should repair it.  The Bob Robert's tutorial didn't sound very difficult -- it is just whether I actually get around to buying the parts. 

   You also mentioned repairing the terminals in the Jamma harness.  How do I do that?  I assume that if I bought a new PCB it would also be susceptible to the same problem if I don't fix those terminals.

   Anyway, Thanks for everyone's input!

Just as it is,
Flip Willie

[northerngames]

theres plenty of the pins left where it should not effect it unless your swiching it out all the time.

there's plenty left to make full contact with the female pins that's why there rather large instead of small.

like I was saying prior all 4 pins 2 on each side are all connected together as one so if one is contacting anywhere on any of the 4 female pins then the other 3 matching connecting peice's are too 

[AwesomeAlbert]

I have a Tekken 2 Pcb laying around, who will give me $30 for it?

[Flip_Willie]

I have a Tekken 2 Pcb laying around, who will give me $30 for it?

  Lol.  I realize it isn't worth that much (Mine definitely isn't with the burnt ends).

Just as it is,
Flip Willie

[AwesomeAlbert]

Flip willie, If you dont want to deal fixing yours ill sell you mine. i  gutted my mortal kombat coverted to Tekken 2 and mamed it.  I have the pcb, the kick harness, marquee, and even the Manual for it. The jamma harness was "modified" a bit.  I was meaning to sell them to get money to change the marquee.  I hate it that people come over and want to play Tekken 2 (because of the marquee), i have to explain how they can play all these other games, except for tekken 2 ! Then they ask, "So why the marquee???"

[Flip_Willie]

Flip willie, If you dont want to deal fixing yours ill sell you mine. i  gutted my mortal kombat coverted to Tekken 2 and mamed it.  I have the pcb, the kick harness, marquee, and even the Manual for it. The jamma harness was "modified" a bit.  I was meaning to sell them to get money to change the marquee.  I hate it that people come over and want to play Tekken 2 (because of the marquee), i have to explain how they can play all these other games, except for tekken 2 ! Then they ask, "So why the marquee???"

    Haha.

   Well, I appreciate the offer; however, if I were going to spend money on another PCB, I would probably try to get a Tekken 3 board.   
 
   Thanks for the offer though.

Just as it is,
Flip Willie
   

[Level42]

http://homearcade.org/BBBB/pace.html