I bought an NVRAM WEEBLY sound board for my Bally Playboy, about two years ago. The board has been working fine for a few months and I did not use the machine for the past 6 months. Now, when turning it ON, everything works but the sound board generates a lot of background noises, like a rumbling. The sounds and various Playboy chimes and melodies are still audible, but the background noise is really obnoxious.

Everything else works perfectly on the pinball.

I was wondering if people have been having issues with these sound boards or if I am just the unlucky one. What would be another alternative to replace the Bally Playboy sound board, short of finding a true Bally sound board for that machine?

Thank you for your help.
Yves

Thank you Barakandl, I will look into these grounds. What you are describing is definitely close to what I am hearing.

Thanks
Yves

No luck so far.....

The Sound board is insulated from the metal shielding on the backbox. I tried using one of the mounting holes linked to the ground, and the humming became even worse. So back to all four insulated posts, like it was when it was working.

Could you specify which pins of the sound board connector should be linked to the ground? Thank you in advance.

Everything else on the machine is working perfectly.

Yves

I was able to locate an original BALLY Soundboard from Big Daddy Enterprises and mounted it in the backbox.
Sound was back with no humming and unpleasant noises. The original sound board sounds a little bit different from the NVRAM, but works very well and is perfectly silent.

DSC06676 (resized).JPG

You can see the new old board in situation, above the fan and next to the transformer.

Yves

That NVRAM sound board worked well for 15 months. Then it started developing the humming noise. I tried checking the grounds but nothing did it.
I am happy to have an original BALLY sound board in my machine now, and will keep the NVRAM board for a future project. It may work better in a different environment.

Yves