Could have been a break inside one of the wires. To find out - hook up an ohmeter across each wire - one at a time of course - and measure the resistance. Then with the ohmeter firmly connected to each end of the wire - flex every inch of the wire while observing the resistance - then push and pull along the entire length of the wire -if it shoots up at one point on a wire - you have found the problem. The reason I suggest this is that if you find the cause eg wire with internal problem - then if you ever have the same symptoms again - you will have a troubleshooting proceedure to use - as will every one else who has followed this thread. Replacing a bad wire is curing the problem - finding out what failed is good troubleshooting practise.
PS - Have a Blessed Christmas.