The Jigging Raps and Pimples were too aggressive of a lure for those negitive walleyes. The minnow on a plain hook looked to be the key. Here in Mn we are allowed 2 lines in the winter......... I mostly fish in a shelter.... my 1st rig out is my deadstick. Red hook, red bead, and 1 or 2 small split shot, anywhere from 4" to 16" away. I usually use a Fathead minnow on this rig cuz they are pretty lively. Second rig is my active rod. I usually have a small black swivel snap on this to change lures quickly. I start aggressive (lures mentioned earlier) and let the fish dictate.
In the situation mentioned, did any of the fish rise or chase your lure but not bite? Then try same lure in the next size smaller. If not try different colors. Then go to different action lures..... different shaped spoons fall and vibrate differently. This rig I bait with a frozen Shiner head (smell is key). This rig rarely stops moving with the response (or lack of) of the fish let me know how to jig.
When fishing with my buddy we have a routine down as to lure/color selection that gets us dialed in pretty quick.
One thing I have found is that if the fish are following and still not biting...... let the jig get to the bottom and thump it.... then pull the jig right back up to or slightly higher and hold it there. Do this as fast as you can. Then hang on.
Just my 2 cents..... Good Luck!
