No output Channels 1-8

[Rick Ruskin]

No output on channels 1-8. All other channels fine. The audio in/out
board was totally recapped about a year ago but I did not test the
machine after I got it back.
All interior connection are fine but there is a row of status LED's on the mainboard
labeled "XIL DeBug." The one in the middle (designated D21 or D22 -
hard to tell) is red while all others are green. Anyone here know
what this means?

 

[witzendoz]

Have a check and make sure that inputs 1 to 8 are not assigned to a digital out option?

Alan.

 

[Rick Ruskin]

All inputs are set to analog. My unit has ADAT in/out and I recall the ADAT out being active all the time.

 

[witzendoz]

I think they are active all the time in one direction, I think you may be right that it is playback.

Alan.

 

[Rick Ruskin]

I'm thinking that the red status light is pointing to the problem but have no clue as to what it's trying to tell me.

 

[witzendoz]

Been a long time since I have seen inside while it's running, don't be surprised if it's aways red? I am wondering if there is damage to the connectors or cable, maybe pull it off and check the pins.

Alan

 

[Rick Ruskin]

A few more clues: Channels 3 & 7 are working properly. All others are
silent. Analog signal goes in but no audio out. The ADAT in/out works
fine and the incoming analog signal sounds fine when listening through
another ADAT interface device. Even though the battery was changed, no
settings get saved. I must re-enter my setup every time I boot the unit
up. Would a power supply problem be causing any or all of these symptoms?

RR

 

[witzendoz]

If the adat cards is working I would check the caps on the output side of analog card, maybe blown, usually through the connection to a mixer channel with phantom power on, or the caps are just old or even bad solder joints.

If the MX is not booting it is probably due to a flat battery on the mother board, just like you have on a normal computer to keep the settings alive when turned off.

The main power supply sounds OK to me.
Alan

 

[Rick Ruskin]

All caps were replaced because of the distorted output on the 6 non-working channels. Now the same channels have no output at all. Battery was replaced at the same time. There has to be something else going on.

 

[witzendoz]

Sounds like the work was not done properly if the working channels are now not working?

Alan.

 

[Rick Ruskin]

The entire board was re-capped. It'd doubtful that just the same 6 faulty channels would be bad if a that work wasn't done properly.

 

[witzendoz]

Sorry I thought it was 6 different channels.

Now it's a real puzzle, I have already mentioned my usual check list. All I can think of is that there may bad / dry solder joints cracked tracking where the D-sub socket is soldered to the board. Long Shot.

Alan.

 

[witzendoz]

Hay Rick,

Send me an email, I have the analog card schematics.

Alan