Have an older mackie analog 8 Bus 8x2x2 board that has random computer noise occurring. Little 1/2 to 3 seconds of random frequencies, very low volume, but showing up on 1-2 LED segments across all 8 channel meters and the L/R as well. Definitely something internal to the board or external power supply. Not coming from any specific channel or inputs (have muted/disconnected everything. Any known problems like this? Sent a support email to Mackie through their website but says right up front they don't support this model anymore (wasn't even a choice for the support request) so I don't expect to get an answer - other than take it to a service center. I have the tools and am qualified to do repairs, even at the component level, but need some guidance as to the cause - if already known. Or if not, a contact that could help. Thanks!