Sydney
Quoted from VDrums2112:So that answers the question on the pops (I have the same issue although the lamp sockets are #555). So what about the #89 LED flashers I bought? All they do is come on at about 25% at power up and stay on continuously. These are the ones I bought.
http://www.pinballlife.com/index.php?p=product&id=1247
-Steve
Have look at the schematic for the 89s - there is a bleed resistor to keep the original incandescents warm - the led is being power through this circuit. Clip the lead to the power resistor and your leds will work, however I prefer the original 89s in this application as they look better when fired as a flash. The leds respond too quickly and don't look as good in my opinion. The 89s fade down gracefully after a flash 
With your pop leds purchase some with bridge rectifiers in them (they'll say good for ac/dc or controlled circuits) or swap the polarity at the socket for the ones you're trying to use. The led is a "real" diode so is polarised.
Casper, WY
