Gang:

My F-14 has a few problems that are switch related. In switch edge and in normal game play, both slings fail to register when closed. When the pop bumper switch is closed, both it and the R sling fires. The L sling never fires under any circumstance.

Here's what I know:

In coil test, all coils fire appropriately.

The MPU was recently serviced by a respected Pinsider who confirmed on his bench that it is 100%. This issue was present, prior to him servicing it.

When I remove the row(J10)/column(J8) connectors and jumper them, they register the correct switch closures.

With the J8/J10 connectors in place, I have continuity from all 3 components back to their respective pins on the MPU and no continuity across other header pins (where there shouldn't be).

All diodes have been tested and are good. This includes ALL diodes in the switch matrix. Only exceptions are 20 and 30-32, which are microswitches without diodes. They did not have diodes on them when the game functioned correctly.

Visibly I do not see any switches that have bent lugs or things making contact where they shouldn't.

Thanks in advance for weighing in!

Xeneize

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zacaj

Means that even when I close them by hand, the coil refuses to fire.

I thought the same thing at first, but they are no where near the switch. My Swords of Fury with similar (micro) switches on the wireform ramps do not have diodes either. Where should I look?

When I close the sling switches by hand, they are nonresponsive.

When I close the pop bumper switch by hand, the pop fires (weakly), and so does the right sling.

I did... not seeing an associated diode on those (20 and 30-32) switches

This is starting to make sense...so the sling switches in the matrix are NOT the ones that when closed, fire the coil. They merely score points when the coil fires and the arm moves toward the center of the playfield.

The vertical switches behind the sling rubber are actually SS (special) switches which are NOT part of the matrix.

The header joints at 1J-18 should be good as the board was just completely serviced, but I will inspect (although I think this is actually 1J-19, see chart below).

Would those be at the switch itself or on the MPU? (Not in front of the game at the moment, but will be after work)

zacaj and GRUMPY - you guys are AWESOME!

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I feel good about header pins, but need to inspect the connectors at J19 and J18 as I was only focused on J8 & J10. I never trust IDC connectors until thoroughly tested.

Will do this tonight.

Update:

So, there is indeed continuity across all 3 switches at the mechs on the white ground line. The white ground line also has continuity to its header pin on J18-7. I double checked the schematic after zacaj 's comment. Even though it clearly calls out this game having a Sys 11A MPU, it also reflects no wire at J18-6 or J18-7.

There is continuity from all 3 of the Orange wires from each switch to their respective header pin on J18.

A break in the wiring does not seem to be the issue.

GRUMPY now this is an interesting question. It took over a year for this reputable pinsider to repair and return my board. When I sent it to him I sent TWO System 11 boards. One was my spare (from a High Speed) and the second was my dedicated F-14 board. Upon their return, I noticed that the ROMS had been swapped between the two boards. When I asked about it, I was told not to worry that either board was compatible with either game.

Should I swap boards and swap ROMS to see if that is the issue? I KNOW that the MPU with the High Speed ROMS in it is a Sys 11A board. I BELIEVE the MPU sitting in F-14 now is simply an Sys11 board.

If I can make the MPU sitting in F-14 now work without swapping everything out, that would be the ideal as the 11A board underwent major surgery due to battery leakage.

GRUMPY Good call. There was no connection to ground from J18-6 or J18-7.

The white ground wire is only running to J18-7. There is no wire running to J18-6. So, I cleanly soldered a tiny jumper from J18-7 to the pad (after scraping away the green mask). Tested for continuity between ground track and J18-7 and get a beep.

Reinstall the board. As soon as I go into test (display), I hear a coil lock on. It's the upper diverter. It stays locked on until I power down. Reboot, go into test, same coil locks on and I stay in test long enough to validate that the pop bumper and the slings' behavior remains unchanged. So, now in addition to the original issue, I have a coil locking on.

Should I remove the newly installed jumper?

Thanks....

zacaj Sigh, I'm a ninny. Not sure how I did it, but you're right - I jumpered to the wrong pin.

Pulled out the original board to inspect it. While it's ugly, the two pins (J18-6&7) are jumpered together AND to ground. Once I duplicated that configuration, everything finally worked...for the first time in almost two years! Thanks to both you and GRUMPY for all the help!