DV ranges are extremely prone to various error codes showing up for no apparent reason, however the E-04 indicates that there is a problem with data feedback from the video drum and this sometimes being purely because the video heads require cleaning, if it doesnt then the drum ribbon cable to PCB connector can be another possible source of the problem, an element of dismantling being necessary to check this. In saying that though, DVL models do frequently display some very misleading spurious error code numbers that are not really 100% applicable to the actual reason for the fault, this happening because the mechanism has various operating position sensing switches etc, and if the mechanism isn't quite locked into a particular position after a loading / unloading operation a safeguard fault condition can spring up, this being the likely reason why many report that firmly tapping (or other more violent measures!) the sides of the case can sometimes make the device start operating again, the action having jolted the mechanism into activating a sensor. There is a wealth of suggested remedies, but unfortunately too numerous to paste into a web page, and it should also be said that its very advisable that only someone acquaint at working with small precision pieces of equipment should attempt to do any work "within" the camcorder casing, as the device could well end up a write off.