the resistor inside the DSD power supply is *not* a fuse resistor. It *should be* a fuse resistor.
Let me say that ANY 4.7 Ohm resistor you use instead of the stock one, will actually make the power supply SAFER.
The 4.7 Ohm resistor is required to limit the peak current to the diode bridge. It has to withstand up to 400 Volt peak voltage, especially when the output current changes abruptly.
I think it is specified for max 50 Volt. It blows out not for excessive power dissipation, but for a dielectric failure. Using it with 220-240 Volts main makes the difference...
The DSD power supply is designed with no safety in mind. From the design criteria to the components used, it is irresponsably made. There are no spark gaps, no respect area between "mains area" and "output area" of the PCB, no feedback optocoupler.
There are no RFI/EMI filters, no suppression caps. The plastic of the case is not self-estinguishing.
While the DSD charger itself is OK, I would replace the stock power supply with any mobile phone charger stabilized @ 5.5 Volt.