robynm
Joined: May 30, 2013 Posts: 10 Location: London
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Posted: Tue Oct 15, 2013 12:08 am Post subject:
Behringer DJX750 input short Subject description: Very high level with only on input hooked... |
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Hey everyone,
So I am trying to troubleshoot this Behringer DJX750 mixer for a friend. The symptoms are as follow:
- When only one RCA (doesn't matter which one) is hooked to input 1 the sound comes out really loud and out the master through both L and R.
- If both RCA's are plugged the sound comes out at a more normal level but louder by about 8 dB on R.
- This only happens on channel 1.
- I do not exclude the possibility that the level and channel 1 is actually normal and all the other channels come out too low. That would still leave the issue of the "merging" of L and R on this channel though. Indeed I can't get the master to reach above -4 dB even when feeding a 0 dB signal with (fader and gain at max) out of a computer through the CD input of channels 2 to 4.
My theory is that there is some sort of short between L and R at some point along channel 1, obviously before we go to master because it happens only on this one channel. I know that it doesn't happen straight at the inputs because the signal is still split when it comes this back PCB. I have been working my way along the components with an oscilloscope trying to find the differences between my observations on channel 1 and the other "healthy" channels but I am getting a bit lost. This thing is full of tiny surface mount and I thought I might ask for help as I keep probing.
Has anyone observed this kind of issue before? Would someone possess a service manual for this thing?
Thanks for taking the time to read.
Robby _________________ I make music |
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