As the copper wires are very thin, it's possible that you may have broken one (or more) of them internally if the cable has been severely strained.
With the display apart, you can carry out a continuity test on each of the wires to check that they are still connected to the pins of the connector.
If your multimeter has a continuity test function with an audible beeper, you simply place one probe on the soldered joint at the end of each wire inside the display (do one at a time) and then check for a beep when you touch the other probe on each of the connector pins in turn.
At least one of the five pins should produce a strong beep for each of the wires being tested, but you may also hear a weaker beep as partial continuity can sometimes occur through electrical components on the circuit board (e.g. between the battery feed and ground contacts).
Reversing the polarity (by swapping the meter probes) can sometimes produce different results on partial continuity results.
If your multimeter does not have a dedicated continuity test function, you can simply use the low Ohms setting instead, and look for approximately zero Ohms reading on each wire instead of the strong beep.
If a wire is broken at the display end of the wire, you may be able to shorten the cable and resolder the wires to the circuit board if the cable is long enough to reach, otherwise you may have to use a new piece of five core cable to extend the shortened cable.
If you cannot find a problem with the cable (all five wires pass the continuity test) then look closely on the circuit board connections for a fractured track on the circuit board which you may be able to clean the track and bridge the gap with some solder if you're lucky.
Alan
