Upper or lower "T" targets?? Check the diodes (with the game off, of course) then check to make sure you actually have continuity when the switches are closed. If both of them test good follow the switch matrix and make sure all other switches in the row and column those switches are in work, could be a broken wire somewhere along the way.

Edit: Sorry, my reading comprehension is failing me this morning - both of those targets are in Row 1 of the switch matrix. http://www.pinitech.com/switch_database.php?name=Williams_F14_Tomcat&printview=1

Same troubleshooting steps apply as a start.

Remember that switches are not always wired in the order they show in the matrix but I'd say it's safe to say you probably have a broken wire somewhere on the common wire for that row. I've seen it many times when although the two wires appear to be soldered to the switch one of them is actual broken just short of the solder, a continuity check with a meter is a good place to start.

Check every switch in the row/column. Could well have a loose wire/diode somewhere.

Since all three are out I would trace the common wire for that row between each switch in the row, and I would start with the switches on the other side of the three that aren't working. So, meter in Resistance (ohms) or diode check mode (beeper usually), game off, one lead (polarity won't matter) on the common post of the switch and the other lead on the connection for that color wire on the next switch that wire runs to - keep following it until you find the break.