So...I bought the mpu9211 from rottendog for my High Speed....it has the 2 blue variable adjust ment pots. I have no sounds at all. I turned them both a lot and still nothing. I times I get scratchy sounds for just a second or two then back to nothing. I was thinking the volume put in the bottom of the cabinet. But cleaned it with electronic cleaner and tested it on the DMM. Tested good. Any suggestions? Also any idea why there is a jumper on W8 and W9?

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I have the same issue Feb22 sticker on the board,no sound and what is jumper W8,W9
running in Road Kings

My question if I may is using a new Rottendog MPU 9211 Board in an Earthshaker restoration.
The game operates with everything working. On power-up, a loud squeal noise is heard for about 2-3 seconds, then goes away.

I have read about this on several blogs, thoughts, suggestions or issues?

The Power Supply board is new, Aux Power Board is new, Rottendog mpu9211 is new, Interconnect board is new, and just last night the Sound Board is completely "Re-Capped", ribbon cables are new.

here is a video letting you hear the issue mentioned:

That's the sound board initial state until it gets the reset signal from the MPU. That Rottendog MPU seems to take a little longer to boot than the stock System 11 board took.

Thank you for the reply. Initial State? The noise? Then there is the "bong" sound. Since making this video, I got a cap rebuild kit, and replaced all the caps on the Sound Board. Told myself that would help lol. And..........no change. Sometimes get the distorted noise for 3 seconds, sometimes not.
Someone commented, if it works "why" worry about it? Just because the game works doesn't mean everything is right. I have a STTNG machine which did NOT have the Tie Back Mod suggested by the factory. Didn't know about it. Yes, I did cook a coil and fry a mini 8 driver board.

So when things seem "off" or "non standard", flags go up that something bad is going to happen

Yes. But sometimes, it's just that newly designed or reverse engineered boards may have oddities when installed. Many have odd issues with specific games that many other users have experienced. Some boards use newer surface mounted components that are difficult to replace, and some are completely redesigned with components from china that are let's just say "not thoroughly tested". For some boards, there's no schematics and for other certain boards, it's just not feasible to repair them when issues do arise. Original boards that are bulletproofed are usually my preferred option for these reasons and many more. The more you know.

Very good post. And worthwhile information for consideration. Until now, I "assumed" newer was better, which is possibly not the case. I am very curious about the complete redesign of the System 11 Power Board, which is drastically different than the original.
Certainly the are times where a board has been damaged badly due to it's poor storage conditions, and/or battery leakage damage, or when the board traces are rotting, a replacement is needed. Your point is very good and information will immediately be used on upcoming machines I'll service. Thank you

I have an RD MPU in Big Guns Same sort of screech on boot, I believe the RD MPU has a short delay before data reaching the sound board. If you unplug the data cable to the sound board the screech is constant.