How can I fix my Corioliss Pro Slimline Hair Straighteners?

When I recently came to use my straighteners I plugged them in and the red LED came on even though they were switched off. When I turned the straighteners on the LED remained dimly lit (as opposed to being bright and flashing when the straighteners get to the desired temperature), and the straighteners did not heat up at all. Any clues on how to fix them?