A & H Zed16FX

[Anonymous]

Hi guys,

Need some ideas. This A & H sound desk came in in a world of hurt. Mono board on Channel 7 corroded, no sound from XLR channel Left. So replaced the mono board, replaced output sliders (they were dirty-sounding, and a good clean didn’t help. Replaced output op=amp on aux board which drives the output to XLR L and R. So perfect signal on right, still nothing on left. Any ideas?

Cheers

[Mike C]

How about the ribbon cable that connects all the input the boards.

Do the other channels work OK?

If the other channels work OK try this…..
– Unplug power from the mixer.
– Disconnect the ribbon cable from channels 1 through 7.
– Take the ribbon cable connector that was plugged into
a known working channel and plug it into channel 7.
– Turn on the mixer and test.

Don’t pull on the cable to disconnect it from the input boards.

[Anonymous]

Hi Mike, All channels work on R output. When I inject a signal into each channel, you see the signal output on the CRO when I connect to R XLR. When I inject the signal into each channel and try to read output on the CRO on L XLR you see a huge dc drop into negative territory. That’s the issue I need to address.

[Mike C]

OK I thought it was just channel 7 with the issue.

What are you referring to as CRO?

Do you have any output on the Left channel at the RCA jacks, headphones, on the meters,
at the insert jack at the output.

Kind of guessing without a schematic to follow the signal path.

[Anonymous]

CRO = Cathode Ray Oscilloscope or just Oscilloscope allowing me to view signal output. No Left channel output at all. No L meter, nothing. Just a negative dc signal.

[Author]

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