I recently bought an EBDLE. It has a loud humming coming through the speakers (see video below). I am not sure what it is and am looking for suggestions fr troubleshooting or repair. I have 5 other pinball machines in the same room running on the same sockets and they are all quiet. So far I have tried removing the fluorescent back glass bulb and unplugged the lighting ballast from the system. That made no change. I unplugged the headers from the mpu board and heard no change. The loudness of the hum increases and decreases with the main volume knob. I put in a new volume pot and no change. Anyone else ever had this n one of these old Bally's? Otherwise all sounds and voices work properly.

I forgot to mention I did float the sound board from the mounts. Hum did not disappear. Pots on the sound board sound clean when I adjust them. I turn them both all the way down and can still hear some hum. KenLayton, when you say recap the soundboard, which caps do you replace? There are tons of caps all over the board. If I need to do them all is there a kit to make ordering easy somewhere or do I have to get them individually.

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Ouch! Nah, it was there when i got it. Has gotten louder. Also we had six machines going and people in and out so it was probably hard to hear. I will probably take you up on the offer. I ordered the kit for the squalk and talk board as well as kits for all the other boards. I figure i may as well do them all since they are all the same age.

I'll post back if this fixes my issue or not.

Good idea on the speaker. I will try that. I did swap the volume pot on the coin door for a new one. No difference.

Recapped the squawk and talk board. That fixed the humming. Now running silent as it should. However a new issue has occurred. As of now I am hearing sound effects but no voice. I've double checked my connections, my recapping placement and my solder joints. I'll start a new thread. Thanks for all the advice.

I didn't replace those because they weren't sounding scratchy when I adjusted them. I did put them in my order so I have them. Good thing because I went back and fiddled with those and my voice came back. I will be replacing those tomorrow. All is well with sound now. Thanks.