Amazon.com: HP Compaq dc7800 CMT Core 2 Duo E6400 2.13GHz 2GB 500GB DVD±RW Windows 7 Home Premium Mini-Tower : Electronics
LGA775 HP Motherboard for 7800 Chassis BTX DC7900 MT Motherboard 462431 001 437795 001 for HP DC7900 7800 MT BTX Chassis LGA775|Laptop Motherboard| - AliExpress
Motherboard for HP DC7800 Small Form Factor PC - Vision IT
HP Compaq DC7800 437795-001 Grizzly Motherboard + Core 2 Duo E6750 2.66GHz CPU - The620Guy.com
Amazon.com: Celeron 807UE 1.0GHz SR0NB Processor Milstead Desktop Motherboard 724726-001 Compatible Replacement Spare Part for HP RP3 Retail System Model 3100 RP7 Retail System Model 7800 RP31 RP78 POS Series : Electronics