i recently acquired my first pinball machine!! a good condition LAH.
im doing my own repairs which work out fine, did some soldering on loose contacts, replaced broken drop down targets, fixed a popbumper, switched a few lights etc.. but one thing i havent been able to solve yet.

the 2 lights above the left scoop keep burning out all the time, specially the most left one. ordered a bunch of 555 bulbs and already went through maybe 10-15 of them for the left most bulb and 3 or 4 for the right one. while other bulbs in the game just keep working
so i thought maybe i ordered a bad batch but when i put in a bulb form another location (a 259) which had been working form the be start it also burned out within a day! so its definitely those 2 positions. measured the voltage with a DMM on DC which showed 12.5V same as other positions which were working fine. i read somewhere on pinside the voltage to bulbs uses some kind of PWM so the 12.5v is not really 12.5v.. but more like averaged to ~6v but as it measures the same as other positions it seems fine.

thats when i was out of ideas what could be wrong. anyone any ideas how to fix this ?

no they are supposed to be 555's according to the manual.
and as i measure the same voltage on other positions, which are working fine, i assume its actually correct.
will try to measure with a oscilloscope when i have the time..

any other ideas ?