Donkey Kong pcb digital sound out

[IC777]

The intro and hammer music is out…bad 8035?

I had a lot of oxidation/connector issues that fixed a lot of things but still missing intro and hammer sound. (These are the digital sounds?) Cleaned the 8035 chip, nothing and tried another 8035 chip and nothing…

Any ideas? Audio board on monitor need to be cleaned or checked out?

Thx

 

[SNESNESCUBE64]

The audio board on the monitor will have nothing to do with it if you have the analog sounds (walking and crashing/thump sounds). The digital section is processed by the 8035 which reads data from the sound ROMs. From there is gets fed into DAC08 which then gets fed into an LM324 op amp equivalent. After the amp it gets mixed in with the analog sounds which then goes the EZ20 amp. If you have analog sounds, the amp is operating at a minimum.

Personally, I'd start by checking those sockets, they are hit or miss but if there is corrosion, there is a chance they are junk by this point. From there if sockets are good, check the ROMs to make sure their contents are valid if you have a reader. I don't know how far you get into the weeds with the electronics, but from there I would start checking signals, see if there is an analog signal coming out of the DAC08 with an oscilloscope, seeing if the ROMs are being accessed at all, ect.

 

[mecha]

I've fixed digital sound problems probably exclusively by replacing the socket. those outer single wipe sockets are an art that I have yet to master.