Switch Fault (entire row)

[Jesder]

Hi Guys,

I picked up a BoP 2.0 a week ago and noticed a couple of switch issues on arrival. They didn't bother me enough to start with, but decided to set some time aside tonight to investigate. I've discovered there appears to be an issue with all switches on row #5.

This row contains Left Outlane (15), Right Trough (25), Skill Shot 25K (35), Right Loop Bottom (45), Lower Jet Bumper (55), Head Mouth (65), Mini Exit Right (75).

The behaviour I see is activating these switches will register the switch directly above it in row 4. The most noticeable one for me was Left Outlane (15) appears as Tilt (14). This is seen all the way along the row (15 activates 14, 25 activates 24, 35 activates 34 and so on). All switches on row 4 register correctly in test mode when activated and do not seem to be affected by the issue. Switches in other rows also activate correctly and do not appear to be an issue. The issue looks to be isolated to row 5.

I inspected the switches on row 5 and think the issue resides with the switch for Right Trough (25). If I remove all balls from the trough and then try to activate any of the other switches on row 5, none of them register in switch test mode.

If I activcate Right Trough (25) with a ball or manually with my finger and then activate one of the other switches on row 5, I get the strange behaviour e.g. Left Out Lane (15) appears as Tilt (14) and Lower Jet (55) appears as Upper Jet (54).

Looking at the right trough switch, I noticed that some soldering had been done to it at some point in recent weeks/months/years (not sure how recent) - and the switch wire (white+green) is connected to the banded side of the diode. I believe this should be connected to the non banded side as per the other switches across the machine.

right_trough_switch.jpg

Right trough switch

(59.07 KiB) Not downloaded yet

Thinking that this switch was causing some sort of short, I disconnected the wire from the trough switch and then tried the other switches on row 5, but none of them register. They only register (all be it incorrectly) when the trough switch is engaged (as a side note, the trough switch (25) would be activating switch 24 - which is marked in the manual as "Always closed" which would explain why there is no 'missing ball' error).

I'm wondering if having the wire connected up to the wrong side of the diode has done some damage to the P-ROC board or one of its chips? Is this possible? Am I missing something simple? Any thoughts or suggestions on things I can try to diagnose it further?

[Jesder]

This looks to be solved now.

I moved the wire to the correct switch lug on the right trough switch. This resulted in no switches on row 5 working. I ran through all switches on the machine and marked them off on the switch matrix to confirm that only the row 5 switches were failing and there were no cases where multiple switches were being reported.

On the P-ROC board, there are a series of LM339 chips which are in charge of the direct and matrix switches on the game. Looking at the P-ROC schematics I found which chip was responsible for row 5. I replaced this chip and booted the game back up.

At this point, the switches in row 5 started to register correctly. That is, until I activated the right trough switch again. At this point, the switches on row 5 became intermittent until they stopped registering entirely and was again left with row 5 not working (but all other switches fine).

I replaced the LM339 chip again and this time also replaced the right trough switch. Booting the game back up and testing the switches again, row 5 now registered correctly and the right trough switch worked correctly. I tested the switches on row 5 on repeat for a few minutes, with a heavy focus on the right trough switch and no more failures or intermittent behaviour was seen.

So from what I can tell, the right trough switch was the cause - not just the incorrectly wired lug, but the switch itself. I don't quite understand why the switch was causing the LM339 chip grief, but it's removal from the machine was necessary.

Since fixing, I've played a number of games on both BoP and Bop 2.0 modes and both have run flawlessly without any switch issues, so I'm considering it fixed