Flash audio hum

I hope this is a simple fix. My Flash has always had what could be described as a loud ac hum at idle. The board is a type 1 version 2 and has been recapped. There’s no hum when connected to dc power on the bench. I also have another board I tried that also has the same humming issue.

I searched the forum and didn’t see anything about this problem.

Anyone else ever have this problem?

Thanks

Dennis

Thanks for the info. The game has a very loud hum that only goes away if the sound board power is removed. Interestingly enough the hum remained even after removing all power to the ps board. The only thing left in the circuit that I suspect is the input line filter. I’ll remove it and see if the hum remains or not. Funny thing though, while I was looking around on line for a possible replacement one website even mentioned that a loud hum is a sign of one gone bad. I’ll report back tomorrow.

Here’s an update. First, both boards have been recapped (electrolytics). Just for the heck of it I replaced the tda2002, no change. The last thing I just tried was to see if it would hum in another game. So I installed it in my Contact pin and it is as loud as when it’s in Flash. Now here’s the weird part. Contact has the older type 1 version 1 board in it. When powered up it has the same loud hum but only for less than a second then it goes away, like a cap charging. I think the next to try might be pulling the caps and checking them to make sure they are what their supposed to be.

Hey guys, great discussion. I haven’t given up on this problem and I’m going to find it if it kills me. As i said before, my Contact pin which has the version 1 board in it is completely free of hum. So for the heck of it I picked up a version 1 parts board off of eBay and recapped and replaced the missing volume control pot. I wanted to see if the lack off hum was a fluke or not. Powered it up on the bench and it works perfectly, no hum like the other. So my next step was to read the ac across all the caps. As it turns out both the ver.1 & 2 boards have about the same readings. The caps on both boards are new and the same manufacturer so I don’t think their the issue. So for now I have a couple of things I want to try so I’ll report back in a day or two. I’m not giving up.