Another thing to try, if the "I" still causes the 30 million to come on. De-solder the out going (the wire heading away from the driver board) row wire from the 30 million lamp. If the 30 million lamp still lights the fault will be in the wiring towards the board and visa versa. You can then work your way towards the board or the other way disconnecting the row wire if the 30 million doesn't light until it does. When you come to a lamp circuit board you should be able to unplug it as the row wire should just past through the plug.

This may help isolate the fault to a part of the loom