Hey guys! This is one of my first posts here, and I hope that I cover my bases as I definitely do not want to waste anybodies time today.

I had a bad Hum and missing sound 15 (In sound test) in my F-14 and after checking the easy things (Grounding,Proms) I came to the conclusion that I needed a new sound board. I purchased another one off Ebay that was rebuilt and 100% tested/working.

Got the new board in and Hum went away and now I had sound 15.

So today I decided to really play some F-14 and after about 15 minutes of playing/machine being on and powered up. I got a multi ball. and the music completely stoppped. I have a video below showing what I mean. See here.

Now if I reset the machine it will normally work again like normal, at least until I get another multi ball then its a crap shoot if it works right or not.

I then grabbed a video of the game going through the sound test, which is located here.

So I tried this with both boards, and they are both doing it. So I don't THINK its a sound board issue as I swapped them out and they are both doing this. I also tried initially swapping the chips from one board to the other to see if it made any difference. No dice.

So I would venture a guess that its MPU related rather than sound board, but have no idea where to go from here. I can get MPU board pics if people would like them but some direction on any specific parts/areas they wanted photographed would be helpful.

Thank you guys a ton and hopefully someone can help me.

So I actually recently recapped the power supply as well, since it definitely looked like it needed it. How could I go about verifying that the 5v is enough? any good way to test it? Sorry I am newer to owning these.

Also should I be ordering replacement ribbon cables? I did verify that they are pushed in, and re-seated them. I can try pushing on all of the proms tho and see if that helps/fixes the issue.

Thanks for your help Everyone.

Edit:

So I went out and pushed on all the proms, and re-seated the ribbon cable again. It played pretty good for a few multi balls in a few games, but once it "Warmed up" it started to have the same issue again, and did exactly the same thing. before that it seemed to play a few games fine. I can tell you the seller of the sound board contacted me and asked me to unplug the sound card, and see if the issue is still present, and from what I could tell it actually IS soundboard related, as the alarm wasn't the same but sounded like normal and the rest of the noises worked as I expected them to.

So Ribbon cable, and checking 5V. any good suggestions? I don't have another F-14 to pull parts out of to test really.

The caps were all replaced recently. I bought a YorkTownParts cap kit and replaced them myself. I am looking for a replacement Cable, and I have tried 2 sets of roms.

Doing some additional troubleshooting for the Sound board seller.

If I disconnect the 3 wire jumper from MPU to sound board, the issue still occurs. which should indicate that the MPU is OK but rather either the connection from MPU to sound board, the ribbon cable or the sound board itself is bad..

My money is either the ribbon cable, or the connections on the MPU are maybe bad. I guess I gotta pony up and buy a cable from somewhere and see if that resolves my problem. If I reflow the connector points on the MPU, that "should" rule out the connections, right?

Thanks for any help.

Also all of my Flippers have the Diodes.

Grumpy,

Can you link me (I can't find a thread easily) Where exactly to test for the voltages on the power board AND the sound board to confirm they are getting the correct voltages.

Thanks!

PS/Edit: here is a picture off the board. Ordered a new ribbon cable and harness from the MPU to the sound board just to be sure I cover my bases.

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So after checking voltages (Thank you Grumpy for the specifics of where to test, I really appreciate it.)

I have

At test point 1 right at start up 4.98 V
At test point 3 I have 12.6
At test point 4 I have -14.8

I am going to venture a guess and say this is most likely my issue. My question is. I have already re-capped the power supply, so I would expect that it is something else on the board, are these all parts I could rebuild and replace or should I save up for a new power supply.

Thanks for the help guys!

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Yeah the issue was the same between the two sound boards. regardless of eproms/ect between them.

I know that if I disconnected the red rear flasher board, that it seemed to help, and the error out did not happen. I then tried just having 4 of the 6 flashers in that bank in the rear of the PF with bulbs, and it didn't do it as much. Generally I had to be flipping a lot While multi-ball was going off, and only then sometimes would it error out. But most of the time it ran correctly, even if the alarm pitch was a bit off.

This damn game. I partially think it could be the low 5v. I had been told by someone that if its under 5 at the power board, then its even less at the sound board, and if it doesn't get the full 5V there can be issues. Buuuuut I don't claim they are right, nor do I have any idea what it could be. Only reporting my findings. This flasher bulb test was because the Previous owner had mentioned that he years ago owned a proto F-14 and had issues with those bulbs all being in the game, and caused issues. Kind of at a loss. The flasher board for the PF red lights, looked fine. It did appear to have been re-flowed at some point, but no broken traces/ect.

Edit: I also reflowed the entire Power board to see if I saw any difference, but alas. It did not yield any result.

Edit Edit: Going to a shop that has a F-14 they are going to let me swap out boards( i am bringing all three) and we are going to see if any of them make a difference.)

Issue shows up with or without hitting flippers. I was just trying to see if I was putting as much load as I could on it to see if it would error (If it were power related)

So I went to Nahbour novelty as he has a test bench F-14. With my MPU and Sound board hooked up with my Ribbon (But his 3 wire jumper harness from Sound board to MPU. I know I am stupid, but it was 1.5 hour drive, so I worked with what I had.) I could get the alarm being off tone, and either ringing longer or short than it should, but it would not completely error out like at home. Soooo, he gave me all of the caps near the Sound portion of the system 11 board, and told me that it was a chance it was related to those. I have replaced them, and alas...... Still no dice. I did however get a few things to happen tonight.

I had the game powered on for almost 20 minutes, and had a few games in it. The first... 4 or 5 multi balls I got it worked fine... Then it started to error out just as I was thinking I had fixed it. However, NOW, it happened (Only one during my whole 45 min session) during yagov being shut down, it hung on a note there too.

So I have no clue. Apart from getting another brand new sound board. I have no idea how to test my machine at home.

tried different area's including the chips right below the battery. No change what so ever. I appreciate your help Grumpy.

Edit: MPU and sound board have been shipped off, pending repair from lockwhenlit