This message was posted on behalf of Intel Corporation
I apologize for jumping late to the conversation.
Your computer chipset is the Mobile Intel QM67 Express chipset. I regret to confirm that information that you already figured out it's correct, the compatible chipsets models for your processor, the Intel® Core™ i5-3320M Processor are;
Intel® QS77 PCH
Intel® QM77 PCH
Intel® HM77 PCH
Intel® HM76 PCH
Intel® HM75 PCH
Sorry for that, if there is something else I can help you with let me know.