You need to figure out if the problem is the boards or the wiring/playfield.
Do the trick of removing 2J2 and 2J3 from the driver headers. Take a diode and a test lead or jumper wire.
With the game on and in switch test mode, nothing should register as nothing is connected. As above, diode band points towards the column (2J2). Touch the diode /wire between the pin for row1 and the pin for col1. That’s the plumb bob tilt,
Strangely both #1 drives are located on pin9 of the connector. Trap for the uninitiated.

You should get one switch indicted closed in the diag. If all switches fire in the row, for any one ‘jumper touch’ the fault is on the MPU/driver. If only sw1 fires, that’s the correct result.

Just remember that on connectors 2J2 and 2J3 that pin1 is column or row8, and pin 9 is column or row1 (kind of opposite what you might expect). Also check the manual for the maximum switch number used in the game, some game switch diags won’t register switches beyond the max game switch. I think firepower will do the whole switch matrix. All modern games do the whole matrix and just say ‘not used’. But on early games the software was new-ish and there was very limited space to write code for the ‘flipper roms’ (system code).

While there, work backwards on the row pins on 2J3 and you should get 1 switch closure per touch. Then move to col2 and do every pin for the rows again. It’s easy to check the whole board switch-matrix this way.
You should *never* have more than 1 switch detected closed per pin-pair.

If you do- it’s a board fault. Maybe a 7406 or more likely the 4049 IC5. Or the PIA. I can’t be sure, but a logic probe would narrow it down, as would swapping PIAs.
Here’s a list I hope you don’t need:-
2J2 pins 1-3,5 (Columns 5-8 switch drives): IC18 (7406)
2J2 pins 9-6 (Columns 1-4 switch drives): IC17 (7406)
2J3 pins 1,3-5 (Rows 5-8 switch inputs): IC16 (4049)
2J3 pins 9-6 (Rows 1-4 switch inputs): IC15 (4049)

And we’re back to the beginning of the thread where you disconnect the switches at 2J2 and 2J3 and use a logic probe to work backwards and see whats’s happening.

So lets say the MPU/Driver switch test checks out 100%. Then we’re back to a fault only on the playfield/wiring. Which would be good, because it is possible to have both.

What can happen is you have a fault like a lane change switch (in the switch matrix) touching +50v for the coil. This is a very common firepower problem. It blows a chip on the driver board. You replace the boards and switch on the game, and it blows that new driver board too. You need to check there isn’t a voltage at the plumb bob tilt (ball roll tilt or credit button,etc..) any of the row1 switches with 2J2 and 2J3 *disconnected* and the game on, to avoid this situation.
If you do have a voltage something is mis-wired on row1 or a wire is pinched in the coin door to power.
Seeing some voltage with 2J2 and 2J3 connected and the game on is normal. But they all should be nominal and match in level for the most part. An abnormal voltage reading points to a problem for that row/col pin. With a logic probe that LED is way to bright compared to the others. But I prefer a DMM on a 20v setting for example as I don’t want to blow a logic probe. I usually only use a logic probe on the bench, where I know my MPU/Driver PSU only puts out 12v and 5v DC.
Actually I do have 2 cheap logic probes just in case. But be careful is all I’m saying.

You can just take out the plumb bob tilt / switch / diode from the game (for home use) and tape off the wires to get it working. And then figure out what it was, once you get the row working. I’m hoping it’s diodes and wiring. That’s cheap to fix, it just takes time. Board repair is a whole other subject.

Let’s hope its a row1 switch diode fault or ground fault (where a wire is pinched on a metal bracket that’s grounded to the ‘braid’). Note that the switch matrix wires (white with stripe/green with stripe) are *not* connected directly to ground. Or to a voltage coming from anywhere but the Driver board. Ever.Or you get this kind of result when the switch closes.
I found another excellent switch matrix article, and to avoid duplicating it here, I enclose the link:
http://homepinballrepair.com/index.php/pinball-switch-lamp-matrix-troubleshooting/#switches-closed

Fingers crossed. -Richard

More likely to be a diode folded over and legs touching near a leaf switch tab, or a wire that’s been trapped under a metal bracket somewhere and grounding... you also get switch matrix wires touching at lamp sockets and picking up a voltage. Suff like that. Good Luck on your tests.

No probs for the help.
That’s a relief, that the boards appear to be ok. It still could be the switch PIA or support chips, but it’s much less likely to ge the case.

So you know it’s likely to be the plumb bob tilt or other diode/wiring in the cabinet (likely).
I would start with the plumb bob. Just remove it from the circuit. Then go through each switch in Col 1 (mostly cabinet) switches. Especially the coin switches as they are so small and the diodes are close to the tiny flimsy switches. You don’t really need any switches in col1 except the start button (credit). You could just wire up credit on it’s own to col1.

Then I’d work down row 1. Check left outside rollover r2c2 (inside rollover too r3c2) next. As I’ve said it can be an unrelated switch grounding out. I’ve has some weirdness that made little logical sense with the switch matrix. You will know once you recognize it. A strange looking diode, solder bridge on a switch, pinched or frayed wire.

Adventure.... lol

Yes, you need to see that 58 in that situation with the PF disconnected - you're simulating the switch so if it doesn't show up, that's likely why the game won't start and your PF wiring is likely ok.

Ouch. That’s not good. Do the whole pin test for at least all of Row1 and Row2 as described above without 2J2 2J3 installed. Write it all down in a matrix and then list the switch(es) that don’t work here. It won't be just sw58 when tested this way. I think that’s an impossible result. Do all of C1 and C2 as well and I’ll let you know what chip(s) are likely to be faulty.

Likely being the key word. You can’t just assume that. As I said- you could have both the boards and the PF now faulty. The fault on the PF can blow the chip, so you still need to be sure you don’t have voltages on Row or Column Harness pins coming from the PF. Otherwise you will blow up a repaired Driver switch matrix as soon as you plug 2J2 and 2J3 back in again. I’d assume that the wiring is still probably good on a new game, but not on an old firepower. Unless you know exactly what happened to blow the switch matrix (plumb bob connected to power) or (lane change switch shorted to solenoid power) or (pop bumper scoring switch shorted to power) Etc... those are typical firepower failure points.
Been there, seen that. Owned 3 firepowers and they all eventually had problems. Usually sound speech, but often driver boards. The original firepower boards are probably easier to repair yourself. Sorry.

Dontcha love pinball.

You need to unplug 2J2 and 2J3 and then use the DMM to check if you have any voltage on the diode (or the other ‘open’ side) of the switch. There shouldn’t be any.

On the switch testing with a diode and wire... the results make no sense to me. How can r1c8 work and the r2c8 does not? Given that r2 works on every other switch? Input levels? Check voltage on all the column drives to ground on the 2J2 pins (with headers removed). Are the all the same? What about 2J3?

The reset (meaning the game reboots?) from pb tilt is def wrong. I’m fairly sure you have a fault on the plumbob switch wiring. As I suggested, take it out of the circuit. I would unsolder the ‘upstream connections to it, meaning the place where it connects to the next row1 col switch. If it’s the first one, you would leave the rest disconnected if you didnt join the wire from 2J3pin9 to the other switches. Note that you still need to maintain continuity to the 2J2 and 2J3 connectors, in this case only for the credit button on Or/white (row3) to start a game.

New Idea:
—————
Personally at this point, I would pull col1 (green/brown) from the header at 2J2 pin9 to isolate the column that’s causing problems. Sometimes you can release tension on the connector and pull it out so it can be reinserted, rater than cutting the wire or yanking the terminal out of the housing.

Then connect up the headers, put three balls in the game and switch it on. You should get attract mode. If it says ‘04’ ‘1497’ on the displays, switch it off & on quickly to get to attract mode.
Then simulate adding coins:
Simulate a drop of a few coins by jumpering 2J2pin9 to 2J3pin6 (yel/wht). Thats a good test. You won’t see any change if freeplay is set.
Try to start a game:
Simulate a press of the credit button by jumpering 2J2pin9 to 2J3pin7. You need to have a diode there as before with the band pointing towards Row3 at 2J3pin7 (Or/Wht).

If that starts a game you know you have a fault on col1 wiring between the backbox to the cabinet. It could even be the plumb bob tilt that’s caused the fault.

I suspect the driver board has a level fault too, maybe a blown cap at C37 or C50. Not sure yet. Could be the input 4049 chip. If you want to send me the old system 6 boards (both MPU and Driver), PM me. I have spare chips and a test rig to check them out.

Uh not just now. I love playing pinball, don’t mind adding mods. This type of fault, nahhh.

Is this your problem with the rottendog board? https://pinside.com/pinball/forum/topic/warning-to-rottendog-327-owners-check-it-now
Also see Pinwiki section 4.2.7 on this link: https://pinwiki.com/wiki/index.php?title=Williams_System_3_-_7

Damn, good catch. I think you might be onto something. Here's a pic of the back of the board they posted, showing how the column 1 header pin was touching ground via the mounting bracket behind the board.

1565824415.png

Right. And the pinwiki link above says that may have caused switch column IC at U17 to fail. But maybe not. Worth isolating that pin from the bracket & trying again.

Electrical tape probably isn’t any good. Once you tighten down the screw, it can just punch through and cause an intermittent fault. You should isolate the metal by doing some file or Dremel work on the bracket as shown.

I actually don’t know much about the MPU327, other than it combines the MPU and driver together removing the interconnection which can be problematic if not repinned correctly. The switch DIP switch settings and schematics don’t appear to be online in a quick search. I was assuming normal setup and original boards (completely compatible) in my posts. This board has multiple (and modified) game ROMs and appears to have made some changes to the original designs... although they may be improvements I can’t comment what effects they may have. It’s also worth noting that they originally claimed compatibility with system 7 games, but removed support for Sys7 - Black Knight, Alien Poker and similar later games.

I have always repaired and used original boards in firepower and my other games. I have done upgrades to help make them more reliable, but again on original boards. At a guess, as it’s concerning row1, col1: IC15 and IC17. I gave chip locations and types in this post above:

If the game is working correctly, it shouldn’t blow chips. Usually a few spare PIAs (general to switch, solenoid and lamp matrices) some 4049, 7406 chips for the switch matrix are enough.

Here is a list of components I made most of these are driver board.
EQUIVALENT COMPONENTS:
Transistors
TIP122 NPN Darlington = TIP102 (SE9302) or TIP120
2n4401 NPN Pre-Driver = 2n3904
2n6427 NPN Darlington = MPSA14 (NTE46)
2n6122 NPN Power = TIP41C or 2n5296
2n5060 SCR = 2n5061 (NTE5400)
ICs
MC14049 Invert. Hex Buffer = 4049
6820 PIA = xx6821, xx68A21, xx68B21, where xx can be MC (Motorola) or HD (Hitachi Data).
740x = 74LS0x, 74HCT0x. x is an even number like (2,4,8)

I have some spare PIAs - if they want like $20+ a chip (which is too much) let me know on PM and I’ll send you a good one for just my shipping cost.
Always willing to help get a firepower running given all the problems you have experienced.

I wouldn’t advise someone to swap in new boards into a game that glitched and stopped working. Not without testing the switch matrix, lamp matrix for shorts and testing and ‘beefing up’ the PSU with new caps and diodes, if needed. But that’s where we are... luckily it looks like the rottendog chips are socketed, so it should be an easy fix.

They’re separate fuses. Solenoids are F2, lamps are F3. No lamps, check headers are not swapped first, the check F3 fuse for continuity off the board. Sometimes fuses look good, and check as open.

Re: Solenoids
Sol 01 Ball release is hidden under the Apron. It’s the out-hole kicker on to the ball ramp.
Sol 08 Ramp thrower is under the Playfield with a hook shaped mech. It kicks the ball up into the shooter lane.
See the plyfield diagram in the lower LH corner here for locations:
http://www.firepowerpinball.com/downloads/SolenoidWiring.pdf

This chart my help. You use the coil wire colors to confirm the connection pin on the driver board. This gives you confidence of the driver transistors to check & replace for that coil. If you set the solenoid self test to fire that coil repeatedly *with the solenoid fuse removed* -the driver board pin (and the metal tab on the top of the correct Tip102) will go to ground each time the coil ‘fires’.

From memory moving from Advance auto/up to Manual/Down changes whether the self test goes through all coils in sequence(auto) or does one coil at a time (manual). You press credit/start to move to the next coil. Works the same way for lamp and display digits tests. A logic probe is the best way to see this happening with coils. If it grounds the pin/tab then *both* the pre-driver and Tip102 are likely to be good and don’t need replacing. You can quickly check all the solenoid transistors using this method, but you must remove the solenoid fuse to use a logic probe, which is easiest.

88246820-D8C9-43A2-B856-A78C0E465514 (resized).jpeg

Give up. Lol

Haha

You need to send out the boards, or learn to run the Leon Diagnostic built into the Rottendog board via dip switches. Please note: If you dip switch for Leon’s test Rom, You *must* remove the Lamp, Switch, Cabinet and solenoid headers. You can’t attach the playfield- power the board at *only* 1j2 connector & run diags. Leon’s diag rom “pulses” all the PIAs and you use a logic probe to trace back trough the circuits and see if the board is locking the coil OR if it’s still a fault on the PF/cabinet. Hey, you may have fixed the original coil/wiring problem and have blown two sets of Driver boards. It’s all in Pinwiki- or just google the procedures for Leon’s test rom. There’s a start to tracing with a logic probe way at the top of the thread. You may find it’s IC15 and/or IC17 for the switch inputs, failing that the PIAs on the driver board. If the board isn’t locking up the coil drive(s) (most likely it’s the board as you say) - then you still haven't found a fault on the PF.

So yes, that sounds like a chip fault on the Driver board rather than the playfield wiring to the coils.