I' glad you got it to work. Why the first cables did not could be a couple things. Light wire gauges or poor cable shields could have weakened the signals or allowed excess noise signal entry. The fact that the early cables did not work with even a pen drive suggests they were faulty in some way.
But power MIGHT be an issue in a different way. There are almost NO HDD's that can operate using only the power available from a standard USB2 port. Further, if the HDD in the enslosure is 3½" size suited to desktop PC's, it certainly cannot operate from such a power source. What CAN work, though, is if the HDD is mounted in an eclosure that has its own power supply module to proved adequate power independent of the USB host port. You have not told us that detail, OP.
The other thing that can work for the newer "Laptop Hard Drives" is if they are designed for use with the new USB3 ports, and ARE plugged into such a port. These drive units can work with the higher power supply available (up to 0.9 A) from the USB3 port. BUT even those units can fail if they are plugged into a USB2 port. They can still function from a data transfer aspect, but at slower data rates, so these units often are sold as "USB2 compatible", but the USB2 port can supply only up to 0.5 A, and that is not enough to spin up the HDD so it can work. So IF the USB port on the TV is only the older USB2 variety, that is not normally enough to power even a low-power Laptop Portable Drive.