Do you mean LED or neon? Neon is very different, but for LED it will depend on many things:
- input voltage (and AC or DC)
- type of LED
- number of LEDs per "chain"
Many LED signs will simply be a step-down transformer and rectifier. If you are trying to fix a specific device, take some photos and let us see. Someone might be able to identify a suitable replacement.
Also, asking for replies via. email will probably not get you many results. Make sure you subscribe to the thread and the forum will email you when somebody replies.