Replace Power RPMPS3420-6 power supply ATX 20+4Pin 115/230V

Replacement PSU for Dell Dimension 4700 8400

The Replace Power RPMPS3420-6 is an ATX power supply built as a direct replacement for the Dell Dimension 4700 and 8400 systems using part numbers K8956 and P8401. It provides a 20+4 pin main connector that fits both 20-pin and 24-pin motherboard sockets. The unit operates on 115 or 230 V input at 50/60 Hz and includes a single fan for cooling. It suits owners of those legacy Dell desktops who need a new-old-stock power module.

Steady output on a single rail

The supply uses a single rail design with over-voltage protection and delivers +3.3 V at 13 A, +5 V at 13 A, +12 V1 at 16 A, -12 V at 0.8 A, -5 V at 0.5 A and +5 VSB at 2.5 A. Rise time is less than 70 ms and hold-up time is at least 17 ms at nominal input voltage. These figures describe sustained delivery rather than a short peak, so the unit maintains stable rails during continuous operation in the original chassis.

Swaps the original Dell module

This unit replaces the factory Dell power supply when the original fails or shows voltage instability. The jump is worth it when the existing PSU no longer holds the 17 ms hold-up time or when the 20+4 pin connector is needed for a motherboard upgrade inside the same case. It is not for builders who need higher wattage than the listed rail currents provide or who require modular cabling for a custom build.