I have Behinger Europort EPA900, One speaker crackles, tried swopping cables etc, but nothing helps, the problem seems to be definitely with the speaker.

The amplifier may have destroyed itself. Take it to a Behringer Authorised Repair Shop for repair.

Get a meter and check the resistance on the speaker. Looks like a speaker may be blown but with the description of the crackle noise from the slide controls you might have a bad pot in the unit or the pot has come loose from the board. This could explain why the speaker blew out

BEHRINGER MX9000 SCH Service Manual free download schematics eeprom repair...

Can't say for sure....there should be a bunch of screws in the back so you can gain access....is this a powered cabinet??...can you dis-connect the present speaker and horn and hook up another just to make a test?? Is the cabinet plastic?? There could be loose screws....Does the cabinet have a recess for a stand??If so, check the retaining screws in that as well....and don't forget to check the grill....

The first thing you have to do is replace the damaged parts and repair any damage to the circuit board. After that you will have to tackle the no audio problem if there is one...repairing the damage might solve everything...and it might not.....it is very hard to tell because I can't see the unit.

Good luck......Behringer does not release schematics....you will have to do it without them unfortunately.....unless you can find somebody who has them...Check for a forum on the net for Behringer equipment...you might be lucky to find something there.

Assuming that you've checked the fuse, and the lights come on...

1) Can you hear any "hiss" from the speakers at all?
2) What have you tried to input into the device? (guitars, keyboards, mics, etc.)
3) Have you reset all buttons to "basic" mode?

Let me know, and we'll go from there...

The effects should be the same as the EPA900 unit. Get the brochure here and look for "Effects Table." Hope this helps! http://www.behringer.com/assets/EPA900_P0431_M_EN.pdf

Is the hum there with NO input cables connected? If not, you have bad cabling. Make sure you use only XLR to XLR mic cables and not the junky ones with a 1/4 inch plug that are for Karaoke machines. These devices usually use switching power supplies and do not have the power supply originating hum of older equipment. If the volume control adjusts the hum, then the hum originates previous to the control which is either in the preamps or the external inputs.

It is unlikely to find a compatible USB convertor for that digital recorder. If it has audio input you can probably use a similar cable to that for the IPOD described next. For the IPOD, get a 1/8 inch STEREO splitter cable that splits to 1/4 inch plugs or RCA plugs to connect to the PA system. Radio Shack will probably have a suitable one.