System 11 MPU Power Supply Special Solenoids

Look at a Williams System 11 power supply out of a Road Kings. Special solenoids worked in test but not in game. Video shows the cause of the problem and what is needed to fix it.

[@davidrendon9838]

My special coil test doesnt fire coils. High Speed. reflowed said header pins. Still nothing. How do you test the caps? thanks.

[@arymonem]

Nice find!

[@mariolopez1747]

On my same power supply Iam getting the 5 volts on test pin 1, and test pin3 Iam getting -14.3 and test pin4 I am getting 14.3 VDC? Is this right? I don’t think this right?

[@viperrwk]

The + and - 12 v are not regulated so seeing 14.3vdc is fine. The only issue is if you had your test leads reversed when you made those measurements. You wouldn't have 5v at TP1 if BR1 wasn't working correctly which would mean that TP3 and TP4 should be correct.

[@mariolopez1747]

Ok thank you so much, I had my black lead on pin2 witch is ground right?and the red lead on pin3 reading 14.3vdc, and then moved the red on pin4 and that reading -14.3 and pin 1 read out is a steady 4.9 VDC.

[@viperrwk]

@@mariolopez1747 Yep all good.