4GB DDR3 Memory for HP 280 G1 Microtower PC PC3-12800 1600MHz Non-ECC Desktop DIMM RAM Upgrade (PARTS-QUICK Brand) at Amazon.com
Amazon.com: Ptcliss 180W D16-180P2A Power Supply Unit PSU Replacement for HP Prodesk 680 800 G3 SFF 480 600 G4 SFF 280 285 Pro G3 MT P/N: L08261-002 901771-004 901771-003 901763-001 901762-002 901763-002 : Electronics
Amazon.com: Li-Sun 240W Power Supply Replacement for HP ProDesk 400 600 800 G1 G2 SFF(P/N: 702307-001,702307-002, 751884-001, 751886-001, 796351-001, 702457-001), Also Works for HP Desktop with 200W Power Supply : Electronics
Amazon.com: 782450-001 for HP 280 G1 MT Desktop Motherboard 791128-001 FX-ISB-8X-3 791128-501 LG1150 Mainboard 100% Tested Fully Work : Electronics
Amazon.com: HP ProDesk 400 G1 Tower Computer PC, Intel Quad Core i5-4570 up to 3.6GHz, 16G DDR3, 256G SSD, DVD, Windows 10 Pro 64 Bit-Multi-Language Supports English/Spanish/French (Renewed) : Electronics
Amazon.com: New Genuine HP Pavilion 500 MicroTower (MT) 200 MT 280G1 180W Power Supply 751589-001 : Electronics