What condition must flex cables meet to be considered for reuse?

For flex cables to be suitable for reuse, they must not be excessively bent or damaged. This is crucial because excessive bending can compromise the integrity of the cable's conductive pathways, potentially leading to failures when the cable is put back into service. Reusing a cable that has been damaged can create reliability issues and increase the risk of system malfunctions.

In contrast, the other options do not address the key factors influencing the reusability of flex cables. A cable being double-sided is relevant for certain applications but not a definitive requirement for reuse. Similarly, requiring that cables be new contradicts the concept of reuse. Lastly, the length of the cable, whether shorter than standard or not, does not directly impact its usability but rather its compatibility with specific devices or systems. Thus, the condition that flex cables must not be excessively bent or damaged is the most important criterion for ensuring they can function safely and effectively when reused.