HELP!! Ms Pac blowing 5 amp fuses INSTANTLY when turned on!!

[klunket]

I just installed a new molex edge connector in my ms pac because the old connector needed to be wiggled around before the game would work- so I installed the new edge connector- cut one wire at a time and followed the procedure EXACTLY- double and TRIPLE checked my work. All wires are where they are supposed to be. As soon as I was done, I hooked the harness up to the board and she blows the fuses immediately when turned on. What the heck is going on??

[John's Arcade]

You sure you did it right? Double check. Seems unlikely that it would suddenly be a problem.

Try isolating the issue. Unplug the board. Does it still blow?

Do continuity tests at edge connector. Bridged connection?

[klunket]

You sure you did it right? Double check. Seems unlikely that it would suddenly be a problem.

Try isolating the issue. Unplug the board. Does it still blow?

Do continuity tests at edge connector. Bridged connection?

Thanks for taking the time to respond, I really appreciate it! I am kind of lost here! The two 5 amp fuses blew once before I put the new connector on- but they were older fuses. They blew once when I was wiggling the edge connector wires around to make the game work. However, once I put new fuses in the game worked again without blowing the fuses. In fact, just this last past Thursday I left the game run all day just to see if there was anymore issues with the fuses blowing. It wasn't until I installed this new molex 44 pin connector with crimp pins that the fuses blow as soon as the power is turned on. Literally as soon as she has power you can see the fuses light up and blow instantaneously.

I am pretty sure that I installed the connector right- I cut only one wire at a time and I double and triple checked each one before I moved to the next wire... It took me many hours to do it because I spent so much time making sure that I wasn't making any mistakes. And I crimped each pin by hand with a needle nose because I dont have one of those molex crimpers, so that was also very time consuming. Then after the fuses blew, I checked my work again by comparing the new connector to the old to make sure all of the wires were in the right place- and unfortunately they are. It couldn't be that easy !!

Here is my biggest problem in figuring this out... Unfortunately I am such an amateur that I don't even really know how to use a multi-meter!! I do have one, but am pretty much clueless... In the past when I restored these old games I always put all brand new components in so there was never any need to do anything like that. I have used multi-meters before but only when I had step by step instructions on exactly what to do. I decided when I bought this Ms Pacman a few months ago that I was going to keep it all original. The monitor works great and except for the poor connection to the PCB everything in this game WAS working fine. There must not be anything wrong with the power supply because it WAS working correctly!! I did unplug the board and the fuses did not blow- so I am pretty sure that it cannot be the power supply causing the issue. The fuse block is also original, but in very clean and good condition... like I said it was working fine except for the edge connector not making a great connection... that was this cabinets only issue- the game would reset right in the middle of playing it- and sometimes when you turned it on it wouldn't work at all until you wiggled the wires at the edge connector- and the edge connector was getting a little hot because of the poor connection. The actual PCB edge isn't perfect, but it's in pretty darn good shape- I have seen them looking pretty toasty in the past. But all of this is irrelevant I guess because the fact is IT WAS WORKING before I switched out the edge connector. I thought this would solve all of the issues , I guess I should have left it alone! If you have the time to explain how to do a continuity test, what to set the meter on and where to put the terminals I would really appreciate it man- I know that is an awful big request. I am just so lost. I threw some pictures with my post here hoping it helps. Thanks a million- it means a lot that you took the time to respond as I am sure you get flooded with people like me looking for help.


http://i72.photobucket.com/albums/i197/klunkit/Mobile%20Uploads/0704160817_zpspdqrdomk.jpg
http://i72.photobucket.com/albums/i197/klunkit/Mobile%20Uploads/0702161105c_zpsi94ziiv1.jpg
http://i72.photobucket.com/albums/i197/klunkit/Mobile%20Uploads/0704160815_zpsangkoqnx.jpg
http://i72.photobucket.com/albums/i197/klunkit/Mobile%20Uploads/0704160816_zpszehm55ov.jpg

[kcase01]

The fuse block looks like the original fuse block and it has problems. I would replace the fuse block with a new one.

[klunket]

The fuse block looks like the original fuse block and it has problems. I would replace the fuse block with a new one.

That is something I was planning to do eventually anyhow, however I don't think it is what is causing the problem since the fuses aren't blowing when the PCB isn't plugged in, coupled with the fact that the game was working prior to the new molex connector being installed... This is so dang frustrating!!

[John's Arcade]

You need to start removing variables.

Unplug the coin door. Power it on. Unplug the PCB, power it on. You need to isolate the short.

[klunket]

You need to start removing variables.

Unplug the coin door. Power it on. Unplug the PCB, power it on. You need to isolate the short.

So far it only blows the fuses when you connect the PCB- disconnect it and power it on and everything else functions, plug PCB back in and BOOM!! There must be something wrong with this new molex connector, but I just don't understand what. I used the multimeter and it is getting the correct amount of power to the right places... something must be touching somewhere and I am just not finding it

[iankellogg]

Bad rectifier diodes. D7 and D8. use 1N5401 or better.