Quoted from vid1900:
Let's start with the 5v section, this always needs updating.
First and most importantly, the C15 12,000mfd 20v Capacitor has to be replaced 100% of the time (C10 is 18,000mfd 20v on Sys7).
Where can I find an 18,000mfd 20v capacitor? It is for a system 7 Black Knight. Does it have to be 18,000?