Hello !
I am brand new to this site and hate to have to start out with asking for help on a problem I cant seem to figure out. My f-14 awhile back stopped playing music. All other sounds/speech seem to be working during the game and in attract mode. I had a fellow that worked at an arcade repair shop come by and looked it over. He told me that it was a bad sound board. I purchased a rebuilt, fully test sound board and installed it today. Still nothing, I have looked the MPU 11a over carefully and noticed previous repair work done on Q72 transistor TIP122, good job in my opinion, but I did see acid damage from the batteries at one time has coroded some of the componets, I took a toothbrush and vinegar and cleaned the areas. I havent noticed any burns. I have double and triple checked all the connections and fuses. I just read where someone was having speaker issues, is this common?Dose the music play thru the bottom speaker. The Eprom at U24 has a sticker on it saying "proto 5" Anybody ever come across that. Is there a way to test it or is it better to get new ones. Sorry for the lengthy story, thanks for any help out there.

Thank you for your input.

Robin, your right, I just tested the speakers this morning and I do have sound/speech coming thru all three. I did remove the flat cable completely and didnt notice a change in anything, I still had sound/speech. It connects to the "Widget I/O" Ok you got me on that one, not sure what a widget is, but I will Wiki it. I guess I could have a bad cable??
Any recommendation on where to get a replacement eeprom for the music??

Brokedad, its an off board part connected by a gray cable, it is very scratchy sounding when I make adjustments to it, I thought about replacing it since it was so easy to get to. I also read on here where someone suggested unplugging the cable, the volume would max out but just to see if the music came back. IDK about this.

OK, meter the cable out, it checks ok, went back and was rereading some tech notes, sometimes this helps, this is what I found.

CPU Sound Diagnostic Switch SW1.
Testing the sound circuitry is only possible after successful completion of the system 11 power-on CPU tests (as described above). That is, the game must boot properly and go into "attract" mode, with no power-on beep tones.

Well I'm getting one beep tone on power up and then after hitting start and shooting first ball it beeps one time again.

It also went on to say...

On the left side of the CPU board there are two switches. The top switch SW1 is the sound diagnostic switch. If you press this button, you should get two test sounds. This shows that the CVSD (Continuously Variable Slope Delta) modulator, which produces the game's voices, and the DAC (Digital to Analog Converter) sound circuits are working.

I'm only getting one that sounds like a bomb drop

Now I'm going try this:

No Sound: sound/speech board is not operating, or a failure is affecting the sound circuitry (broken or disconnected cable, dead amplifier, bad speaker).
One Tone: U23 RAM chip error.
Two Tones: U21 ROM chip error.
Three Tones: U22 ROM chip error.
Four Tones: U21 ROM chip error.
Five Tones: U22 ROM chip error.
No Sound when CPU switch SW1 is Pressed (but sound heard during diagnostic tests).
Check the sound select inputs (U9 pins 2-9) with a logic probe to see if they pulse during Sound Test 01. Also check the -12 volt supply voltage on the CPU board. If this voltage is low (or AC ripple seems high), perform the following checks (you can check for ripple using your meter set to AC volts; more than .75 AC volts is probably too much AC ripple).

Thanks Brokedad ! That's some great info.

I just went into the sound diagnostic, test 1 thru 9 produced sounds and voice but test 10 thru 17 were quiet. Could that be from a bad eprom?
What can be done for an eprom thats bad, just replace it, right.
Do you test them or program them?

Well after getting a new sound board, freshly programed proms form Brokedad, and checking the ribbon cable, wires, transistors, fuses and potentiometer, I still get sounds and voice but no music. Has anyone ever seen traces on the pcb board lift and wrinkle. I found several spots around the mpu 11a board. Wonder if that might be an issue?