Can i replace my lenovo g580 20157 motherboard with a g580 2689 motherboard that uses the intel hm76 chipset? Cause i tried a core i3 2350m in my notebook and it worked fine, just shutsdown every 30minutes. Then i found the intel hm70 chipset is limited to celeron and Pentium dual core cpu's. Mine also only have one ram slot? Is that normal?
Don't know what you mean by "normal", it's whatever design the manufacturer uses for their laptop. There is no single standard way to design a system. I have seen quite a few laptops with only one RAM slot. Not a very good design for upgrading but it's "normal" I guess.
About swapping the motherboards, you would have to contact Lenovo or do a lot of research about exactly what the differences in the models are. You may find out that the motherboard fits, but the video connection is wrong for your screen or some other connector is 1 inch further and your cables can't reach it. I would just sell your laptop and get one with the motherboard you want. By the time you are done buying things, testing it, you would have been better off just buying the laptop you want.