So I bought this WRT310N a couple years ago. It's always been flaky, but I paid too much for it and I can't bring myself to get something different. It has always flaked out during periods of high load - torrenting and multiple simultaneous users always brought the wireless network to a standstill and caused dropped connections. Various manufacturer and 3rd party firmwares made no difference. Probably overheating, amirite?
I always meant to do something about it, but I have a habit of living in a dream world when I "mean to do things", so I never did. My goal this year has been to . or get off the pot.
After acquiring a free backup router in case of failure, I ripped the the WRT310N open. One tiny little heatsink on the switch, nothing on the CPU or wireless radio. Touching the heatsink was painful it was so hot, and the CPU was just as gnarly. The wireless radio chip was just warm. I chopped up an old Northbridge heatsink I had kicking around, and stuck them on the switch/CPU chips with some random Coolermaster paste and a little drop of superglue in the corners. I left the cover off, with a 80mm fan was used to blow air over the bare board. After a month of uptime and rock solid stability, I considered it a complete win.
Then I hacked up the case to make the cooling solution permanent. Pressure fit a quiet 40mm fan, soldered it to the board, and opened up holes for the heatsinks to poke through. Heatsinks are stay cool to the touch (They'd get quite warm without active airflow!). It ain't pretty, but it works. I love it. I'm so stoked.
i have the WRT54G2, the moment i saw your mod made me think why not give it a try with my router
these "little guys" is the only thing i cant think of for now to have my "improvised heatsinks", not bad with the clearance from the top covered back.
if too lazy to hunt for those 60mm fan, i'll just drill tons of holes with the top cover instead.