First post, by jwt27
I'm currently trying to fix an XR385 card here. I discovered the voltage on pin 8 (power-down function) of the DAC (AK4510) is at about 1.5V. It should be either 5V (power down mode) or pulled down to 0V (normal) by pin 15 on the CPU (H8/3002). When held at 0V manually, it works again.
I lifted pin 8 from the circuit board to check where this 1.5V originates. Turns out it's coming from the DAC itself. This would suggest the DAC is broken, however it does seem to sound fine when this pin is at 0V.
This might be useful information for anyone who has a broken XR385. Can anyone check this? Maybe it's a common fault in these things. I thought I had a two more broken cards but one now suddenly works again, and I can't find the other one anywhere.
WANTED - Manuals/drivers for:
- Tecmar Graphics Master
- Paradise Autoswitch EGA 350 (EGA1A)