Hi everybody, I have a Williams Blackout that is very close to being finished and thanks to the wonderful people here on Pinside I have managed to bring it back to life. I thought I would bring the topic out in the open so that maybe more people could see it. When the left flipper is flipped multiple times or just occasionally the soundboard calls out "Mission Completed!" this happens whether you have completed the mission on the playfield or not. It does not add score but it is very annoying because it happens intermittently when the left flipper is flipped. It never happens when the right flipper is activated. The soundboard is brand new from Jeff kohout at Pinball PCB. All the other boards in the backbox are original. Other than this, the soundboard fires exactly when it should with correct sounds and sounds fine. It was brought to my attention that maybe the coil on the left flipper had high resistance and was causing power ripples through some of the boards in the back box and causing the soundboard to fire. I checked both coils and they both measure the same at 1.2. I verified this with coil resistance chart expert John Robertson in Canada. If anyone reading this has any idea what it might be I would really appreciate some pointers...Many Thanks!
IMG_20210301_214549 (resized).jpg

The right flipper has the lane-change switch. I can flip the right one a million times with no issue. If I can find what trigger causes that particular phrase to fire maybe I can repair it. Or maybe it's just random. I took the diode and the double wire off the left flipper coil the other day and measured the resistance and then I soldered everything back together so I know that diode is connected. Unless it's bad.

Hmmm, interesting. I'll try and slap the cabinet around. "Bad Cabinet!!"

No speech calls by banging on the cabinet. Tilt works!! Lol! It's definitely activated by the left flipper every 7th or 8th flip in a series....

I just put the machine in test mode and went to switch test. There are no stuck switches. Flipping the left flipper during the switch test makes the soundboard call out "Mission Completed! Pounding near The Flipper switches or flipping the right flipper multiple times does not trigger the speech call. My flipper coils have three lugs. I desoldered the diode on one end and the double blue wires on one side and checked the ohms rating. I did this with both flipper coils and the ratings came up the same 1.2 and about 26 when I switched the leads around to different lugs. I did notice a crack in the housing on the left lug but the wiring is firm and connected, I did a continuity check...
IMG_20210321_133830 (resized).jpgIMG_20210321_134050 (resized).jpg

Upon closer inspection, there is a good sized crack in the side of the N4001 left flipper diode. I replaced it with a new N4004 diode. I've attached a magnified picture, the crack is right down the seam of the original mold of this diode between the 00 and the 03 imprint right through to the exiting lead... I have now flipped the flipper 100 times and there are no speech call-outs! Mystery solved! No doubt now that the faulty diode was causing issues within the power circuit triggering the sound board. Thank you to everybody that pitched in here!!
IMG_20210321_141642 (resized).jpg