I have an old Samsung TV that worked fine the last time I used it but yesterday I hooked it up to cable and I only have channels 2-13 working. I dont have the original remote anymore so I purchased a universal to access the menu which worked except the menu has no options to help. Any channels above 13 seem to scrambled and fuzzy. Any suggestions.
You are correct n diagnosing your problem. You are using the terrestrial broadcast tuner to tune in cable. The reason why 2 through 13 work is because analog cable and analog broadcasts use the same frequencies for both.
Without the model number, I have no way of telling you if it is or is not cable ready. If it is, you will need to find an option in the menu or a switch somewhere on the front or rear of the TV to put the tuner in cable mode. I will say that unless the TV is really old, it should be cable ready to at least 100 channels.