F-14 Tomcat
Williams, 1987I have talk and background sounds but no music on my F-14 Tomcat. PinWiki don't talk much about sound problem troubleshooting.
I can't see what model the sound card is but at boot up I get 1 bong. I have a logic probe and a radio shack oscilloscope to help troubleshoot with. Any help would be greatly appreciated!
EDIT: D-11581 Sound board
Music is generated from the sound board while background and speech is generated on the CPU. Check ribbon cables from sound board
Done. I ohm each leg for continuity to make sure that the cable was good. Ill also re-heat the solder points to make sure there is no cold solder joints.
Thank you for your reply!!
Maybe also try re seating the Roms on the sound board. If you get the bong, the board is booting up and supposedly ready
I found this post that said that the oscillator (CR1) was the problem, sure enough I have no pulsing at the oscillator.
https://pinside.com/pinball/forum/topic/repair-williams-system-11-d11298-f-14-tomcat-sound-board-no-music-snd-10
EDIT: Never mind, I tested the wrong oscillator....
No music in test mode, but you have speaker amplification of the CPU generated sound fx? If so, your FM synthesis chip output is the issue.
It could be a few things. Might not be enabling, could be a faulty summing opAmp (U16), faulty Yamaha FM chip(s) could be bad (U9, U10, not likely though), etc. Try re-seating the FM chips first. Suspect something very simple here first. Check voltages on the audio board. Make sure it has +5v logic power. If that doesn't help...
The FM output comes off of U16, pins 1 & 7 for the two channels. You can probe those pins for DC voltage of any kind while in music test mode. You can also connect an old junk pair of headphones or even a piezo disc with leads coming off it after the DC coupling caps (c5 & c6) to listen for a very faint FM output. If you see/hear nothing, probe the non inverting inputs on that opamp (pins 3 & 5) and check for voltage in test mode. You're just looking for anything wiggling around that would indicate audio playback. You can audio probe there too, but with no coupling cap, you'll be applying DC to that speaker source (so don't use something you care about). You should also see +12v on Pin 8, and -12v on pin 4 of that 1458 opAmp.
If you see nothing there, I have some other ideas for you to try.
Quoted from Brewchap:Is this board like the early Williams boards that need the capacitors replaced?
You should replace the electrolytics on these, minimally the larger value ones for the audio amplifier ICs. I think people often overlook the audio boards, but they need power filtering too. Are any of the caps vented or puffy looking?
Quoted from thedefog:You should replace the electrolytics on these, minimally the larger value ones for the audio amplifier ICs. I think people often overlook the audio boards, but they need power filtering too. Are any of the caps vented or puffy looking?
No sir, the caps look good, but I am going to order a kit to replace the caps. And I will start on your suggestion tonight after dinner. Thank you!
I re-seated all the chips that was in a socket. I also test pin 1 and pin 7 on chip U16. I only had 4.8 volts on pin 1. Nothing on pin 7.
Now I'm tearing apart the house to find some kind of headphone to test with. Having 2 boys, there should be something laying around.
Quoted from Brewchap:Thanks gutz I'll give that a shot. Now I have to try and find a YM3012.
i've never seen one of these yamaha chips fail, but it isn't impossible obviously from that thread. Have you probed the soundboard cpu or pia bus for activity?
No, I better do that before I try to find a chip. Looks like that chip will be hard to get.
I got caught up last night trying to find some headphones or ear plugs.
Quoted from thedefog:i've never seen one of these yamaha chips fail, but it isn't impossible obviously from that thread. Have you probed the soundboard cpu or pia bus for activity?
Cpu is pretty active, the PIA, only half of it is active.
Cpu
1 Low 21 Pulsing
2 High 22 Pulsing
3 High 23 Pulsing
4 Pulsing 24 Pulsing
5 Pulsing 25 Pulsing
6 Low 26 Pulsing
7 High 27 Pulsing
8 Pulsing 28 Pulsing
9 Pulsing 29 Pulsing
10 Pulsing 30 Pulsing
11 Pulsing 31 Pulsing
12 Pulsing 32 Low
13 Pulsing 33 Pulsing
14 Pulsing 34 Pulsing
15 Pulsing 35 Pulsing
16 Pulsing 36 High
17 Pulsing 37 High
18 Pulsing 38 Low
19 Pulsing 39 Low
20 Pulsing 40 High
PIA
1 Low 21 Pulsing
2 High 22 High
3 High 23 Pulsing
4 High 24 High
5 High 25 Pulsing
6 High 26 Pulsing
7 High 27 Pulsing
8 High 28 Pulsing
9 High 29 Pulsing
10 High 30 Pulsing
11 Low 31 Pulsing
12 Low 32 Pulsing
13 Low 33 Pulsing
14 High 34 High
15 Low 35 Pulsing
16 High 36 Pulsing
17 Low 37 High
18 High 38 Pulsing
19 High 39 High
20 High 40 Pulsing
Quoted from Brewchap:This is fixed by changing out the MPU
I'm going to guess you have a damaged trace on the bad MPU there going from the data/address bus on the sound cpu/pia to that connector. Luckily you had another board to test with there. Makes it easier to debug now. If your sound 6802/8 CPU on the bad MPU was faulty, you'd probably not get partial operation. It would just not work. You have voice, so your CSVD and D/A section is good too.
I'd do continuity checks from the sound CPU & PIA to the connector pins on the bad MPU. If not a trace issue, the PIA is probably suspect.
Brewchap Did you have any luck fixing your issue? My Williams Big Guns runs a similar sound board but a slightly different revision and the background music dissapeared. Ive had a good look at it the best i can but couldnt find any issues ive tried the basics. I also sent the board away and they guy couldnt find any issues with it but he didnt have a pinball setup to test it properly.
There was a lot of acid damage to the MPU that was causing my sound problems. The MPU was in very bad shape, so I replaced it and have not had any problems since.
Quoted from thedefog:I'd do continuity checks from the sound CPU & PIA to the connector pins on the bad MPU. If not a trace issue, the PIA is probably suspect.
Try changing out the PIA and see what happens.
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Vandalia, OH