Check IC3. It is mounted on a heat sink near the big filter cap.
If you haven't replaced the electrolytic caps yet, do that to see if the deflection comes back. Go over all of your solder/traces at the same time to look for bad or iffy looking solder.
If the caps are new, solder looks good, and still no deflection, you should probably replace IC3 with the exact same part number (other K7000 models might have a different part number).
Worst case - measure the ohms between the yellow and green wires on the yoke connector. they should be somewhere around 12-15 ohms...