Re-attaching A Cable To A Circuitboard
If the cable has some form of flat connector like faston (google it) you can insert the male part in the female part. If there are no connectors, the wire was badly soldered to the board and went broke, so you have to buy a solder iron and (Preferably lead tin alloy for ease of use) solder wire and solder it on again. If you don't have experience contact some tv repairman or radio amateur to get it repaired.