Build Your Own Arcade Controls Forum
Arcade Collecting => Pinball => Topic started by: qrz on September 08, 2008, 11:51:38 pm
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my arcade customer had me take a look at one of his pinball units today .
strange symptom as it seldom did the same thing twice upon pwr up..... ?
decided it must be a syscon issue . suspected a reset problem as it had some other random problems as well.
C30 ( 22uF @25v) is the C part of the RC time constant for the reset generator.
wasn't too surprised when it measured out at 15 uF and an esr reading of 350 ohms .
replacing the cap eliminated the start up symptoms.
next issue was the knocker and ball launcher would alternately kick , then also noticed the "ferris wheel" wasn't rotating .
fault was traced to a missing 25v source . the ground sides of rect bridge br1 were open.
replacing the diode restored normal ops :)
sure glad he had a schematic !!
qrz