I have a DJM 500 all the EQ / pots and Gain pots were getting old and making lots of noise/ crackle ... a friend of mine was using it for while and thought he would clean it with switch cleaner.... only he used one that has melted the internals of the rotary pots .... so they all need replacing a simple re-solder wont cut it, also a few of the cue switches are broken too..... can i get the whole top channel board with the EQs, Gains, Cues on it as a spare part or do i need to replace all rotaries separately ... is this going to prove to be more expensive than its worth? ..... it seems a shame to just throw it in the bin........

Hi, the crackling noise means it needs a service, was it stored in a shed or garage ? As damp storage is the likely cause.

Sounds like it might not be cleaned enough. They may have done the pots but the internal circuit boards may not have been done enough.

I would replace it or you can use crock pot liners 9pretty cheap) which is what my wife uses

There is a contact cleaner spray available at most stereo, tech stores, that may assist you with your dilemma. The pots or potentiometers are dusty. You could even just use air also to clean them out better. Just some advice hope it helps..

This is usually caused by oxidation in the potentiometer (fancy name for your volume control, also called a pot). The solution is to buy a small spray can of tuner cleaner, then unplug the amp and partially extract the electronics chassis from the case -- usually by removing screws in the top (but NOT usually the top handle screws), then gently sliding the chassis forward until you can easily see and reach behind your gain knob. You should see a squashed metal cylinder attached thru the faceplate to that knob -- that's the pot. It will probably have 3 wires attached -- don't worry: these never have voltages high enough to feel even when the amp is on. Either near where these wires are attached or elsewhere on that cylinder there should be one or more small holes. Using the small plastic tube that came with that spray can of tuner cleaner, spray a small amount of cleaner into the pot, then turn the gain knob from maximum to minimum and back several times. I usually do this by plugging the amp into a receptacle and moving the knob this way BEFORE using the spray, listening for the noises, then I spray it, manipulate the knob as described and hear the noise disappear. Unless you're confident about doing that, DON'T! Instead, slide the chassis back into the case and plug the amp in, then see if the noise is gone. If so, put in all the screws and you're done. If there's a noticeable improvement, but still some noise, move the knob bank and forth a few more times to see if that fixes it; if not, unplug the amp, slide the chassis out again and repeat the spraying procedure one time, then reassemble the amp and plug it in. If your problem is still not gone, you'll have to replace the pot. If you know how to solder WELL, you can order another volume pot thru a Marshall dealer or online, OR you can remove the pot and take it to a local electronics store where they can probably find an equivalent potentiometer at a lower price than the genuine Marshall part -- be sure to ask for one with "an audio taper" (a logarithmic change in resistance that corresponds to how audio amplifiers control sound). Good luck, and please post your results on this website.

Use the stereo master outs from the DJM into the A and B Inputs of the EQ (you'll need 2 phono to Jack or 2 phono to XLR cables) then from the A and B Outputs of the EQ to the power amp/ speakers, etc (you'll need jack or XLR cables depending on what is powereing your speakers)

The bass pot's / controls are notorious for becoming dry jointed, all that is usually needed is the controls resoldering.

http://www.technicsdjuk.com/

The rotary controls / pot's (especially "low") on DJM500's are nototious for becoming dry jointed, usually a quick resolder of the legs / connections sorts them out.

http://stores.ebay.co.uk/methleykev

Ask the schematic finding experts -
They will get it for you.

http://manualfox.com

apply some spray (lubricant contact cleaner)from radio shack-----to master gain volume and move it up and down many times.