Bad Hiss on Channels 3 and 4

[Johnny B]

Hi folks, I have just joined this forum, I was on the old forum a couple times.
I have a problem which is driving me nuts!
The board and cpu boot up fine despite a brief error 43 message. I have recorded with the board and no problems until recently - before you ask, I have not changed anything recently.

However, channels 3 and 4 are lighting up the levels to about halfway, and when I push the faders I get what I can only describe as 'white noise'. It's a fat hiss. I have removed the board from it's desk console, disconnected everything except for the Mackie Power and Data cables (and a pair of powered near fields running off the control room out).....no improvement.
I have removed the bottom and disconnected each of the 3 fader ribbon cables and it still happens.
I then read that the ribbon from the power distribution PCB to the DSP PCB can cause these kinds of problems so I removed it, cleaned and reseated it....no fix.
So I need some help please. Here's the details of the problem.

The trim pot is all the way off, Press select and assign (as you would to make that channel 'live') and push the fader and hear a 'white noise'.
LEDS are constantly lit to halfway even if channel is muted.
It does it with nothing into the board at all (see above)
As soon as it is fully booted they light up and are showing on screen too.

Inside I see the ribbons from the faders go to a centrally mounted PCB. On this PCB there are 2 LEDS illuminated. One flashes green and the other a constant red. (Green for good, Red for broken?)
I've spent 3 days this week fighting with this beast....I could use some back up.
Glad to see a nice forum set up since the other site 'died'.
Glad to be here.
Johnny B

[Johnny B]

On the other hand, can anybody recommend a good Mackie Tech Store please?
Many thanks
JB

[Crash]

Inside I see the ribbons from the faders go to a centrally mounted PCB. On this PCB there are 2 LEDS illuminated. One flashes green and the other a constant red. (Green for good, Red for broken?)
I've spent 3 days this week fighting with this beast....I could use some back up.
Glad to see a nice forum set up since the other site 'died'.
Glad to be here.
Johnny B

The red and green LED's you see flashing are transmit and receive indicators for communication between the console and the CPU. I would not read much into anything you see there.

Have you waded through any of the info here?

http://www.sonido-7.com/d8b/index.html

Loads of useful info. that may be of help.

S&X audio in Seattle is the place to get a d8b fixed, if you decide to go that route. You can Google them, they are out there.

[Johnny B]

Hi Crash,
Yes I have been right through that site, but thanks anyway.

I also contacted S and X, Seattle, spoke to a great tech guy who told me right off, "it's the DSP board"

So I'm on the hunt for a DSP board......anyone?
Thanks again
JB

[Crash]

SteveT has a connection that may be of use in your quest....