ThinkCentre M58 CPU upgrade

[ThinkPad560X]

I have a ThinkCentre M58 tower, witch was the last year of the Core 2 Duo desktops for ThinkCentre before moving to the Core i series. Right now my ThinkCentre has a stock LGA775 Intel Dual-Core Pentium Processor E5300 2.60GHz. I bought a LGA775 Intel Core 2 Duo E8400 3.0GHz for $10 to upgrade my tower to. The problem is When I installed the CPU "Did all the cleaning and new thermal paste" I get 3 beeps in a row that make 12 beeps total, so 4 3 beeps. I reinstalled the stock CPU and its working fine now. I did a test and removed my Core 2 Duo out of my ThinkCentre M55e tower and has the same specs as the Core 2 Duo only it is a E7300 2.6GHz. Installed it and got the same beep error. Not sure why this motherboard is not accepting a Core 2 Duo CPU?

Motherboard spec: 7373CTO Serial: MJTD386

[axur-delmeria]

1. Have you checked if it has any BIOS updates?

2. It's possible that the processor is defective.

[RealBlackStuff]

+1 for bad CPU.
Why not update to a nice Quadcore, such as this: Q9550, 2.83GHz, 1333FSB, 12MB

[ThinkPad560X]

What about the M55e Core 2 Duo? It works fine on it's board. I'll try to see if there is a bios update. The latest is 2009.

[RealBlackStuff]

M58 BIOS from 2012: https://pcsupport.lenovo.com/ie/en/downloads/ds013586

[ThinkPad560X]

I already got it, but thanks for the link. The latest was 5/7/12 and I installed the bios and reinstalled the C2D and it works now.

[axur-delmeria]

Ah, so it was a BIOS issue. Good thing it worked out in the end! A Q9550 would've been nice on that machine, though I dunno if it's work the extra power consumption and heat.