Quoted from Nikrox2:
Man I hate to bug you again Wayout but when I found the loose wire I just alligator clipped it and got everything working. Then left it that way. For some reason I thought I’d really fix it and solder the connection. Well the loose wire was at the center drop down solinoid (to go up the roll over ). It still works but now everything on column 4 is out again ! Ugh. Nothing else was touched. Used a ceramic low voltage solder gun. Checked all fuses. Looked thru the harness 100 times before reaching out. Did use the existing diode. Can change it out if that cou
Do you mean all the switches in column 4 are not responding? If absolutely every single switch in the column is not responding, you should perform this test to determine if this is a board problem or playfield problem:
Testing the Switch Columns (all system 11 revisions).
To test the switch columns, do the following:
Remove the backglass and fold down the display to gain access to the CPU board.
Unplug the connectors at 1J8 and 1J10 (lower portion of the CPU board).
Turn the game on.
After the game boots, go to the Test menu's "Switch Levels" test.
Connect your alligator test lead to pin 9 of 1J10. Pin 9 is the left most pin, as facing the board.
On the other end of the alligator test lead, clip on a 1N4004 diode, with the banded end away from the alligator lead. Touch the banded end of the diode to pin 1 of 1J8. Again, pin 1 is the right most pin, as facing the board.
The display should show switch 1 is closed.
Move the diode/alligator lead on 1J8 to the next pin. The display should show switch 9 is closed.
Repeat the previous step, until pin 9 of 1J8. Switches 1, 9, 17, 25, 33, 41, 49, 57 should be closed on the display as you move forward, pin 1 to pin 9, on connector 1J8. Note pin 6 is a key pin, and should be skipped.
If a particular column number does not display as closed, or is closed without any test lead connection, there is a problem on the CPU board. Usually this is a bad switch matrix column 2N3904 transistor at Q42-Q49.