Comentário oficial
Does this problem occur when the DDJ-1000 is not connected to anything else except the power? If it does not, then the issue may be another unit in your setup which has an electrical short and improper grounding, causing the power to go to the chassis of the DDJ-1000.
If this problem DOES occur with only the power connected to the DDJ-1000, then there is a short within the DDJ itself, and you should either return the unit to your retailer or contact Pioneer DJ technical support in your region to have your DDJ inspected and/or serviced.