Hi,

I had a similar problem with a series 10 Ibanez pedal and thought it was the switch causing the grief. However, on closer inspection I found that the input jack socket was ever so slightly loose in its housing (it could move down about 1mm). So, by inserting a thin plastic shim at the top of the socket, to 'force' the socket down ever so slightly, I found that the LED went on and have had no problems since!

Not sure if this will help, but good luck!