Vintage Synth Repair

Hi Everyone, 
Its an ALesis QS-8 weighted keys. ( I think Fatar is the maker). It works perfect except that E2 will lose volume after being played 1 to 3 times after power up. The condition will repeat each time I power down and back up. The problem also affects the MIDI modules. 
What I have done thus far
1. Removed the contact boards and cleaned the carbon impregnated contacts on the double bubble strip
2. cleaned the contact points on the board. 
3. Cursed a lot after trying this 3 times. 

It seems like its a voltage drop.I am not sure as I am not as electronically savvy as I like to think. No one anywhere has posted a similiar problem that I can find. 
There are 2 contact PC boards. The entire unit is in pristine condition and there is no evidence of damage. 

It drives me nuts as its exactly right 1 to 3 plays and than it drops no other keys have this problem. Your input about my output is appreciated. Thanks. Brian