Page 1 of 1

Black Knight Ball Launch Fix

Posted: Tue Aug 21, 2018 7:17 am
by RichPundit
Original Post: "Bought a Black Knight pin last year with LEDs & Topper for $1800. It worked well. Haven't played for several months cuz have epilepsy & the flashing lights are a problem. However, recently put on the market for local sale, & the machine works except for the ball launcher. The balls stay in place after repeated resets. The wire connections look solid, have 3 balls in place & batteries are good.

Please help! Tx - rich (Appleton, Wisconsin)"
From Toyguy @Pinside:

"<blockquote cite="#4537848">Put it in coil test and see if balls kick out to the plunger lane. If not, maybe a wire came loose on the coil. If that test is OK, remove all the balls, raise all the drop targets and go into switch test. See if all of the ball trough switches register as you roll balls into the drain. If any balls are in the lock, it could also be those switches. It won’t start unless it sees 3 balls.</blockquote>

Status: ran Diagnosis ok until Solenoid Test. None of the solenoids fired. Is this a blown fuse or something else? Obviously am inexperienced with these kind of repairs. Ur thoughts are appreciated - rich
BKf3 2017.jpg
The attachment BKf3 2017.jpg is no longer available

Re: Black Knight Ball Launch Fix

Posted: Tue Aug 21, 2018 4:44 pm
by Eric_S
Probably a blown solenoid fuse on the power supply board. My guess is one of the driver transistors shorted out, causing a coil to lock on and blow the fuse.

Good repair info here: http://www.pinwiki.com/wiki/index.php?t ... stem_3_-_7

Re: Black Knight Ball Launch Fix

Posted: Wed Aug 22, 2018 6:53 am
by RichPundit
Eric_S wrote: Tue Aug 21, 2018 4:44 pm Probably a blown solenoid fuse on the power supply board. My guess is one of the driver transistors shorted out, causing a coil to lock on and blow the fuse.

Good repair info here: http://www.pinwiki.com/wiki/index.php?t ... stem_3_-_7
Makes sense … Tx very much!