New Dell Power Supply PSU Switching Unit Optiplex GX520 GX620 GX280 210L 320 330 740 745 755 Dimension C521 3100C 280W JK930 MH595 MH596 NC912 NH429 P9550 RT490 U9087 X9072 AA24100L D280P-00 H280P-00 L280P-01 H280P-01 L280P-0 L220P-00 AA24120L N220P-00 PS genuine oem dell part power supply psu for dell computer - desktop / small desktop form factor 280w power supply switching unit psu for dell optiplex gx520 gx620 gx280 210l 320 330 740 745 755 dimension c521 3100c part numbers: jk930 mh595 mh596 nc912 nh429 p9550 rt490 u9087 x9072 model numbers: aa24100l, d280p-00, h280p-00, l280p-01, h280p-01, l280p-0, l220p-00, aa24120l, n220p-00, ps-5281-5df-lf, h290e-00