Hi,

I recently bought a Jokerz pinball machine with a music failure. I have replaced the sound ROM in U5 on the audio board which didn't solve the problem. Running the sound test works however fine as with the volume control. When starting the machine I got the error message "music failure". There is no acid damage to the MPU board which is labled 557 (originates from a Big Guns). Pressing the sound diagnostic switch on the MPU board results in a two tone signal. Ribbon cable between MPU board and sound board has been changed. Power supply board has also been replaced.

Any idea what could be the cause to the music failure?

Thanks!

Here is a picture of the MPU and sound board.

IMG_8992 (resized).JPG

IMG_1606 (resized).JPG

Yes the error existed before replacing any of these parts.

I had finally some time to swap the mpu boards between my Earthshaker and Jokerz but no difference except that the speech got very low on my Earthshaker using the mpu board I took from Jokerz. Any idea why?
I have also replaced the oscillator and both the Yamaha chip on the Jokerz sound board but with no difference.
So not sure where to start next..