Add earth from 5volt 10 amp power pack plus positives only from rgb panels no earth need a lead from Jumpers to shield pinball machine input gnd pin from power pack

[psmmacker]

 

I was getting flicking signal in my p3 9n the left panel

Do i did some gnd testing and found a solution that the earth on the back of the rgb

May not be used i still powering my stm via pc power usb

but looping the earth stright on the stm32 discovery frount jumper from the power pack 

Keepiing the 5volt + as normal from the back of the rgb panels as the iec cable aka hub75 has 3 earths gnds

And it seems to cure my issue

Thanks paul