Crumar Musical Instruments User Group.

Hello,
This is my first post to this group. 
I am now using the Spirit synth that I purchased new in the 80's and have 
finally got around to actually playing it. 
Problems with power. Although the keyboard is in pristine condition, maybe 
it's having problems from sitting in the case all these years but to get 
power to the unit you have to wiggle to power cord in the back. 
Now here is the weird problem. When I get the power cord to make contact, and 
the "on" rocker switch is lit, the 2 lights (in Mod X and shaper Y) won't go 
on.
I gentle tap on the right side of unit gets those 2 blinking.

What I've done: opened it up and checked all connections. It looks spanking 
clean inside and all connections look solid.
Anyone have any ideas?
I'm not an electrical engineer, but do use common sense, i.e., if a 
connection isn't working I replace. I've been fixing all my vintage guitar 
equipment this way for years.
Thanks,
Bob