Hi everyone.  I am struggling with my space invaders Deluxe.  I followed the instructions I found here.  http://www.brentradio.com/SpaceInvadersSoundRepair.htm. 

I replaced all caps on the sound board, changed the  lm3900 at M5 and replaced both the 74174 at E5 and the 7417 at F5.

I am still getting a very high pitched scream when I coin up.  The sound exists throughout the entire game.  Also I don't have any saucer explosion sound.  I am stumped at what is going on.   Any help would be appreciated.  Thank you

in case this ever gets researched, a fuse on the power supply had blown.   I never would have thought a fuse on that would have only impacted the sound.  Problem solved.

So I was done fixing up my Rally X and unplugged the board in order to move it downstairs.  I plugged it back in backwards. The screen was orange and I realized my error.  I turned the connection around and it will boot up and play but now I don't have any sounds.  Any idea what I ruined on the board?