Atari Asteroids high pitch sound

[shovelhead]

HI all,   I'm fixing up an Asteroids game and have everything pretty close to working except I'm getting a high pitch sound over the speakers with the regular game sounds.   It is driving me crazy so for now I unplug the speaker.   Here is what I have done so far on this item;  1. Inspected the door sensor or warning sensor for damage and or pinch or touching.   This Change door sensor is  not bent or touching and appears to be just fine.   2.  We tested a sound board off a working game and same result.

Any suggestion's would be appreciated.   I'm new to the forum but I've fixed this game up over 7 years ago and keep it going cause its a lot of fun.   

[iankellogg]

I wonder if its from the monitor. I am actually not too surehow to fix it right but a good place to start is to make sure everything is grounded included the monitor and coin door

[shovelhead]

thanks for your suggestion.
I sent some pics of the test screen to some folks and recorded the sound as well.   The Grounding could be an issue so Im checking that today.  The sound is a WARNING sound as if the Change door was having an issue.   
The change door is inactive now and possibly the power to it not being connected feeds the warning sound.   Ill look into this.
  thanks again.

ANY OTHER suggestions?

[iankellogg]

Saw your klov thread. I'm not too sure if its the AR2 or the slam switch. as you can actually play with the slam switch and get it to work right. Might be worth rebuilding the AR2