I recently purchased a new stick of ram, to upgrade my desktop. I then installed it into my desktop, with another - the original- stick of RAM. I then turned on my computer, only to hear a periodic, long, and unchanging beeping noise being emitted from my computer. After some research I found that it was an error message, indicating a BIOS ROM checksum failure - Possible MB failure. 
So far, I have tried:

• Resetting my BIOS data, by unplugging the coin cell battery connected to the memory.
• Resetting my BIOS data, and changing my RAM, to only the one stick, and both of the original sticks.

During this time, I realized the RAM clock speeds were different (even though they were not indicated on the original sticks).

Is there anything I can do aside from purchase a new motherboard?