I have a high speed that was locking on the left lower kicker (Q75) . I pulled the transistor off of the board, and the the lower right kicker locked on (Q71). When I pulled that transistor the upper left pop bumper locked on.
My thoughts are now my issue lies up stream. Is this a PIA issue? Or prior to that.
I see this in the Pinwiki that looks related: https://www.pinwiki.com/wiki/index.php?title=Williams_System_9_-_11#Special_solenoid_problems
"The usual cause of special solenoid circuit failure is a stuck switch that locks the associated solenoid on, causing the TIP-122 transistor to fail and the coil to get so hot that the winding insulation melts (causing a reduction of coil resistance, eventually approaching zero ohms). The zener diode (pictured, left) in the circuit may fail shorted as well. This will cause the associated coil to lock on even after repair of the other damaged circuitry since the zener is connected directly to ground. The shorted zener diode causes the 7402/2N4401/TIP122 circuit to react identically to a switch closure. Gack!"
The 7402 and the ZR1-6 zeners are always suspect.
If a Zener is shorted, the coil will lock on when a game is started or when diagnostics starts.
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Chris Hibler - CARGPB #31
http://ChrisHiblerPinball.com/Contact ... for board repairs
http://www.PinWiki.com - The Place to go for Pinball Repair Info
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Enfield, CT
Dunakeszi