Basically a LED comes off and on instantly compared to a regular bulb has sort of a delay before it's bright enough for the eye to see that it's on. In the lamp matrix there is enough ripple voltage to barely light the leds. Basically they will look like they are barely on and sort of have a flicker to them when the bulb is not supposed to be on. Sooooo what does all of this mean? Basically you want to use nonghosting leds in any lamp matrix driven bulb. (Inserts, etc) You can use normal leds in the GI circuit for the playfield and backglass. In early Bally/Stern insert leds will ghost even though you are using non ghosting leds. You have to get a alltek lamp driver board or there are other solutions out there to fix that.