We replace the cable, not patch it - a spliced or re-tensioned cable is a callback waiting to happen, so we don't do it. Both cables get swapped together even if only one failed, since they're the same age and under the same tension; replacing one and leaving its match to fail next month costs you a second trip. We check the drums and the track alignment at the same time, because a cable that's frayed from rubbing against a bent track will just fray again on a fresh cable. On the higher-end doors we see in this price bracket - heavier insulated panels, sometimes custom sizing - we match cable gauge to the actual door weight rather than guessing, since an undersized cable on a heavy door is the fastest way to end up back at this same job in a year.