Haunted House
Gottlieb, 1982Hi all,
Due to a weak vuk on the lower pf I decide to do the suggested modification with the bpdb. It works fine, so far so good, however the vuk now pops everytime when one of the non mpu controlled coils ( such as kicking coils or flippers from lower or main pf ) gets energized .What could be the problem ???
IMG_6559 (resized).JPGThe popbumper board is getting some noise from the solenoid GND lead...… What usualy helps is changing the input filter. Change the input cap to 1uF ~ 2.2uF. What also helps is running a seperate GND wire to the popbumper Ground point to the mainplayfield. But this requires some wiring and an additional connector.
Marco
Hi Thierry, I keep haunting you 
Change C1 to 1uF or 2.2uF, 10V or up. You can use a small ceramic cap or a polarized one (tantallum or electrolytic). When using a polarized capacitor beware of the orientation: the postive lead connected with the trace to resistor R1 and the negative lead to GND (use your Fluke to beep out with the negative side of C4 (47uF) if you are in doubt.
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Zemst
Zeist
Barnegat, NJ