No spark on my 75 CB550F

Howdy...hope someone can help me out.

I don't have spark on my CB550F. I bit of history on the bike; I just got it last weekend from this guy who said that he was changing the handle bars and once he finished he couldn't get it started. A buddy on mine just came over this morning to look at it...checked the usual suspects; points (good), battery (new), plugs (good condition). Electronics was his kryptonite so he couldn't figure out why I wasn't getting any spark.

I lights and horn work so I don't think its the battery. I just checked the birds nest of wires behind the headlight and everything seems to be in order, I did find a brown female connector without a partner but according to my Clymer brown is for the taillight and that works just fine.

I was trying to find a thread for this on the forum but nothing was working...can anyone offer help? Thanks.