It is a proprietary psu using white 8 pin and cpu 4 pin.  difficult to upgrade above stock 240w.  the optiplex 5050/5060/5070/7080 all use different proprietary 6 pin instead of 8 pin. form factor of psu is also nonstandard. [IMAGE]     If really need to upgrade, consider non-Dell TFX psu such as TX500 Gold and use 24 to 8 pin adapter.  [URL] [URL]
Can the OptiPlex 5040 MT power supply be upgraded? If so, Is there a part number or other vendor info available the upgrade?
Upgrade the OptiPlex 5040 MT power Supply?