Weird Millenium Bypass Fix

[Yorick]

My led wasn't working in my Biyang Chorus so I decided to fix it and replaced the standard sk30a with a j201. To my surprice it didn't work even though the circuit is the same as this one:



I could get it to work by placing a 16.5M resistor parallel with the diode. It works so I'm chuffed, but I want to know why it didn't work despite the fact that it is exactly the same as the above circuit.
Not really a problem as such but I just want to know why it works now to learn from it!