I have a Laser Ball pin that I have been working on for some time now, almost a year. I tried fixing the system 6 boards and got to the point that I bought an Rottendog MPU327. Now the pin starts, but there is still a few issues that I thought that a new board would fix. I still have a (one) pop bumper , 2 kickers and the 3 drop target banks not working. (and a kicker that shorts out)

I thought that I should tackle one problem at a time and start with the Drop Target, but I don't know where to start. I had hoped that the boards replacement would have fixed all this.

No sir, it does not. Right now I am doing the coils test in the diag menu to test all solenoids. This is how I know that the other solenoids are not working also.

How do you jump the transistor? And how will I know which transistor to jump? Easy to find on the system 6 assy drawings, I don't know how the Rottendog is set up.

I "think" that the transistors are labeled the same as the system 6 boards.

Thank you for your advice zacaj. I took a spare wire and attached it to the grounding strap. I grounded out 3 coils which fired until I developed a dead short blowing the fuse on the power supply. This pin will be the death of me. lol

I fired solenoids #02, 20, and 22 before I tried to fire #04 (drop target) is when I found that the fuse was blown. At this time I can't replace the fuse without it blowing. Somethings is touching somewhere.

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ok I typed this thing 3 times all ready. not sure what is going on. lol

2J12 #22 blows fuse

2J11 with all (grey) wires disconnected on the solenoids , the fuse keep blowing. I found that with the playfield disconnected the fuse does not blow. off to narrow it down a bit more

2J11 info is not correct. Found gray wire touching solenoid. back to testing.

2J11 #06, 07 and 08 blows fuses.

(2J12 #22 blows fuse)

So over all I got a total of 4 shorts.....

2J11 #06, 07, both diodes tested bad, and the coils tested good per http://www.pinwiki.com/wiki/index.php?title=General#Testing_a_coil
2J11 #08 and 2J12 #22, Both diodes tested good but replaced and the coils tested good per pinwiki.

Going to install 2J11 #06, 07 (dbl drop target bank) to test.

Still blowing fuses. Tested the gray wires to ground and they ohm to ground.

zacaj, After double checking my findings, I found that I had the meter set in the wrong position.
I also checked the wires up to the board connector and no problems.

One diode blew out of the four. All coils and diodes test good now.

I tested each coil one at a time to determine if the fuse would blow or not.

Do you test a fet the same way as a transistor?

I found a way to test the Fet. https://pinside.com/pinball/forum/topic/how-to-test-a-fet-transistor

I'm going to read this again just to wrap my head around it.

Still working on this one

I identified 4 Fet's and the "Q" numbers on the Rottendog seems to match that of an system 6 board.

So I have pulled and ordered replacement fet's, so it will be a week or so before I can start back on troubleshoot the Drop Targets. So I turned my attention to the lone pop bumper that will not fire. I have 27 volts on the switch. The coil ohm out good and the diode is good but was replaced anyways. Grounding the switch will not make it fire either. What would keep it from firing?

No sir, the coil does not fire in the coil test or fire when grounded. Sorry, after reading my last post, I made a mistake saying that the switch had voltage. I meant that the coil had voltage.

I swapped two pop bumper coils as suggested, but the problem did not follow. For peace of mind, I thought that I will change the 2J12 connector out that attaches to the Rottendog board. The pop bumper and two other coils (#20 and #5) that are not firing, is own this same connector.

Bottom set of switches in the stack.

20171217_154858 (resized).jpg

Here we go! The pop bumper fired this time. I also blew the fuse I guess cause I held the ground to long to the lug. I also blown the diode because the fuse blows right away.

What does the resistor and the capacitor do for the pop bumper?

I replaced 2 coils today and now have all the coils firing when I ground to the non banded side of the diode. If the coils are firing now in this manner would the resistor / capacitor now be suspect?

I have great news! All solenoid now fire in the coil test and all switches work. All 3 drop target banks work and reset at game start up. During game play 2 drop target banks do not reset once all targets are down. What do I need to look for to fix this issue?

Zacaj, I had a set of pcbs that was installed upside down keeping the drop targets from resetting. My wife is now playing the pin, pointing out what needs to be adjusted. She looks to be having a blast!

I wanted to thank you for your help and taking the time to answer my questions as I learned how to repair this pin. Without your help, I'm sure that this pin would still be in a non-working condition. Thank you very much for your help sir!

I have some question concerning game play. I get random tilts, random awards of new games and the high score remain 50,000 even after beating the high score. Strange stuff.

Thats my fault, it was a type-o

This is what I found so far. It seems that the roll over stars is causing the problems.

Star number 1 causes the Tilt and Left Kicker to activate.
Star number 5 cause the Drop Targets to reset.
Star number 7 cause the Drop Target to reset and the Upper Kicker to activate.
Stars number 6, 8 and 10 do not score.

Also activating the Stars can produce random awards of new games, but not one stands out as the cause.

I tested all the diodes and they tested good. Surely this will not be another board problem because I'm not sure where to look.