Question re: system temperatures

I've done no overclocking, no advanced work whatsoever. Every time I try to google my issue, all of the solutions seem to be based around the person with the issue overclocking their system thus causing high tempuratures. This is not that issue.

On to the actual problem, my motherboard reports temperatures of 69c when running any program that takes any worthwhile amount of system resources (and some that don't), in particular, most games. CPU and GPU tempuratures seem far lower, around 30-40c. Assuming the sensor isn't to blame (and it isn't, if the feel of the case is any indication), are there any reliable ways to lower MB tempurature with simple BIOS and power settings?

Running an old F1a55-M (FM1) on Win 7 Home Premium, SP1.

EDIT: The motherboard idles at 47, which also seems high. I've changed locations for better airflow several times and wonder if I just flat-out need a larger case.
 
Fans are running at full, and though I thought dust might've been the issue, clearing it out doesn't seem to help. I admit, this problem's only been in the back of my head as my system's been running like this for over a year, but I had a few back-to-back harddrive failures and it put me on edge about everything, temperature included.
 
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