It had an Intel E210882 board with 2.8Ghz cpu, The Sony part number for the OEM board is 178930631 or 1-789-306-31
I was told a different board can be hard to find that will fit, there has to be something that will fit it's an ATX. I am looking for the board and CPU combo.
Newegg.com has a gigabyte g41 board with e5200 retail boxed cpu for $124.95 that would give you a better cpu and board. Any micro atx board should fit your sony case. The newegg combo deal is under "cpus and motherboards" subsection under cpus.