We have a 24 channel analogue desk, and I want to ensure that all the sends and inputs work consistently and soak for a long time. I also have a few other boxes that I need to test, as we have an intermittent fault somewhere in our output signal chain, but it is too intermittent to do a listening test a.k.a. I don't have that much time. I thought about getting an interface and writing a bunch of test cases firing white noise in and checking that there is no band passing/dropouts on the outputs, but that is quite time consuming, although if it has to be done it'll have to be done. What is the generally accepted way of solving these issues?
Send white noise from your ipod and computer as having a constant signal will allow your ears to more swiftly notice if there's even a momentary drop-out. Route it through your main output chain (I don't know your set-up, you may have to try this with multiple routes if you aren't sure which chain the drop-out is in).
Then go through your system physically. Bump into the console a little bit, wiggle the cables, wiggle them at the amp (be gentle!) look for any cables that are loose that could have their slack stored in a safer manner, and keep listening.
When the drop-out is intermittent over a long period, in my opinion it's probably a physical issue with a cable or jack somewhere that will respond to being jostled, bumped, changing temperature, or even a sub rumble in frequency can jar loose a bad cable temporarily.
Repeat this process in different configurations but if you can't find anything, add a little notebook next to your console where anyone who uses it can write down any errors or dropouts they notice - write down what was happenign at the time, what kind of material was going throuhg the system, what buses, inputs and outputs were in use...soon enough the common element will reveal itself! And the note-taking really doesn't take much time out of your day.
24 Channels is not that huge, if you are just looking to test every channel on the console, get an SM58 and go channel by channel testing for signal (from your voice) to either your main outs or some kind of internal headphone monitor. Should not take more than 10 minutes to move the cable down the line on the back of the console and test every channel. Once you have tested all the inputs you can test the sends (unless you want to test every input to output buss combo).
There really is no quick and dirty way to do this (that I know of). I would not spend the time wiring up an interface to the console and sending white noise etc. You can move a known good SM58 down the line of inputs in half the time. For what its worth thats how I test all my consoles.