I don't think a game squeak on power up is an issue.

I do think you should check the ribbon cables to help with the DMD. They are probably loose on the boards.

This sounds like a sound board issue. You can swap the sound board with WCS or no Fear to confirm the issue.

This distorted and ghosting issues on the DMD sounds like the High Voltage on the DMD controller board is too high. Check the -112v, -100v, and 68v on the DMD power cable. If you install a ColorDMD, these voltages would not be needed and you would have color.

Again, you could swap the DMD or the DMD controller board to a number of games that you have to confirm the issue.

Agree that the squeak is not a DMD issue. I have several games that do the same when they are powered up and the sound comes from the speakers.

Also agree that you should check the DMD supply voltages. Quite common for the power supply on the DMD controller to have burned up components and go out of spec.

the noise is the amplifiers on the sound board initializing. it has nothing to do with the DMD.

My Road Show makes this same high pitched squeak.
Do I need to address it or is it nothing to worry about?
Thanks.

Can you post a picture of the sound board?

is it indicative of a pending problem that should be addressed?

My corvette has always done the same thing for a few years now.

My TOM used to have this piercing squeak at power up. I can't recall if removing the C37 and C45 is what fixed it or if it was the 2 larger capacitors that I had replaced. I did this 3 years ago and I remember doing both the same day. I'm not sure if I tested the board once I cut the 2 capacitors off.

I had removed these 2 capacitors based on Pinwiki http://www.pinwiki.com/wiki/index.php?title=Williams_WPC

6.24.6.5 Scratchy Audio or mumbled speech
During production of WPC-95 games, Williams removed two small ceramic caps (C47 and C51) from the A/V board to clean up the sound. This fix can also be applied to the DCS sound board. On the DCS board (Corvette, Indy 500, WCS94, JD, TOM and others) C37 and C45 are the equivalent caps to be removed. Simply clip the caps from the board. You do not need to desolder them. This cleans up the sound and speech on some games like Demo Man quite well.

WCS (resized).jpg
Indy 500 c37 and c45 removed (resized).jpg

The power-on squeal is not an issue, other than it's stressful to your ears.

here's an interesting point... if you have a Rottendog power driver board, the squeal is much worse. that's because of how the voltages come up on the RD driver board. they use different voltage regulators and caps... The caps charge a bit slower, so you get a worse 'squeal' at power on. It bothers people, but it's not doing any damage. But i have to admit, the rottendog squeal is really nasty.

curious, clay...

do you agree with cutting the caps off to remove the squeal?