Jul 212019
 

I got this board a few years ago when I got a Pac-Man cabaret cab that had been converted to Trojan.

The whole cab was sold to me as not working so I assumed the board wasn’t booting either I converted the cab back to pacman and put this board aside until this year

So I fired up the board and it booted up just fine. However there was absolutely no sound coming out.

One of the issues with this board is that there aren’t any schematics available for it.
Luckily the sound section is almost identical to Ghost n Goblins.
Since the traces are visible on the board, I drew them for help on the back of the board.
Crude but it helped figure out things a bit.

It’s got that same sound module (85H001) to drive two YM2203 (3 channel sound chip)
The signal is then fed to a YM3014 DAC, and LM324 Op-Amp and a final HA13001 power amplifier.

Probing the YM2203, YM3014 , LM324 I can see signal coming out of all these and into the input of the power amplifier .

 

However there’s nothing coming out of the HA13001 so I’m assuming this is the culprit here.
Removing it, half the legs broke off . No wonder it wasn’t working

I fitted a new one and the sound came back right away and I was able to enjoy a quick game of Trojan

A quick and easy one but you need these every now and then

And as usual, for those who prefer the video format: