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Author Topic: williams cyclone - fix  (Read 2907 times)

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qrz

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  • wrangling electrons since 1978
williams cyclone - fix
« on: September 08, 2008, 11:51:38 pm »
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
« Last Edit: September 09, 2008, 10:16:51 pm by qrz »