Mk1 loud static noise

curtislv426

Well-known member

Donor 2013, 2016
Joined
Oct 25, 2013
Messages
3,194
Reaction score
1,418
Location
dayton, Ohio
Hi guys. My MK1 PCB is making a horrible static noise. I can't even hear any of the game audio. I checked my Edge connector and all my voltages are spot-on. I also cleaned the edge connector. I replaced the ribbon cable that connects to the audio board. I also checked the header connections on the Soldier Side and I'm getting the correct voltages there as well. Do you think I probably just need to replace the capacitors?
Thanks,
Curt
dba02ec2eb3d692e61e02453ed8cc01d.jpg
 
this is indeed a capacitor issue. I have to replace the caps on mine at home eventually.

the caps seem to go on this model sound board the most apparently. the NBA Jam TE at work you couldn't even hear anything at all. it was like the pot was either monumentally dirty or not hooked up at all.
 
this is indeed a capacitor issue. I have to replace the caps on mine at home eventually.

the caps seem to go on this model sound board the most apparently. the NBA Jam TE at work you couldn't even hear anything at all. it was like the pot was either monumentally dirty or not hooked up at all.
hi mecha I believe you're right. I took a closer look at the board and around the capacitors I noticed a discoloration. I overlooked it the first time because I was looking for a more obvious color like it white or lighter brown or something. Is there somebody on here that sells a little cap kit for this Is there somebody on here that sells a little cap kit for this soundboard?
 
Have you tired cleaning the volume pot with deoxit? The pots are open to the elements and sometimes get rusty inside.
Hi Kev. I don't think it's the sound pot because I disconnected the potentiometer to see if the volume would Skyrocket and it made no difference whatsoever.
 
I had one recently that had no volume control and loud static as well. I replaced the amp and the game sounds returned, the volume control returned, but I still had static, but it was considerably less. I suggest replacing the amp and the caps. Probably fix you right up. HA13116 is the part number of the amp you need.
 
I had one recently that had no volume control and loud static as well. I replaced the amp and the game sounds returned, the volume control returned, but I still had static, but it was considerably less. I suggest replacing the amp and the caps. Probably fix you right up. HA13116 is the part number of the amp you need.
Okay great. Thanks. I'm looking right now on the website at my local electronics store. They have high temperature capacitors as well with the tolerance percentage that I'm not familiar with. Should I just get the regular one or do I need this high temperature one with a certain tolerance? Here's a couple pictures of what I'm talking about. Thanks
c24b307d7c6fd8aa3b5e840dee785bda.jpg
541288bfcdaff3436632eeb415afade4.jpg
 
You always want the 105 degree caps, whether it's on the PCB or the monitor chassis.
Thanks my friend. I think I'm going to replace the 9 capacitors first before I replace the sound amp. I'm still a rookie on my soldering skills.
 
Thanks my friend. I think I'm going to replace the 9 capacitors first before I replace the sound amp. I'm still a rookie on my soldering skills.

You'll want to replace the axial caps as well as the radials, the axials can be a bit tougher to locate and are just as prone to failing. Replacing only the radials would be like changing the distributor cap but leaving the original rotor on a car.
 
Last edited:
If you change the axial caps, I can confirm that electrolytic caps will work as replacements if you have a hard time finding the correct axial replacements.
 
Alright guys, I replaced all the capacitors including the axials. I replaced the sound amp and the potentiometer. I have made improvement but I still have some heavy static on startup. It does get significantly better though after a couple minutes.

What action should I take now?

Thanks
 
I assume you are running -5vdc to it?
Yes. I'm connecting the game through my Mortal Kombat II cabinet using the JAMMA harness through it. Had this game working for a couple of years now. And then recently the static started. And that's when I noticed that the Caps were leaking
 
Do you have any other boards to test with, to rule out the speakers or wiring as the fault?
Yes. I've got lots of other boards to test. Everything works as it should and sounds great. Mortal Kombat 3 and Mortal Kombat 2 work perfectly. And anything else I put in it. Something has happened to that soundboard that I can't notice. maybe a bad ROM chip or something or resistor is out of whack
 
Back
Top Bottom