Im running beta build ver3 40559 yes I believe the stock linksys firmware is still in the other partition but cant boot into it, because my power led light isnt working, only my lan, 2.4ghz wifi and 5ghz. The led bulb for power is busted. So I have no idea how to do the 30/30/30 without the power led ref.
30/30/30 is a reference to a reset method for the ancient WRT54G series routers. Ignore that; never do it.
It's not related to partition switching either.
Hardware reset for your router is simply hold reset button for 10 seconds while it has already been powered on. It's used after verifying a successful flash when having entered a new firmware environment (stock Linksys, DD-WRT).
Triple power cycle method to switch partitions:
Power ON and when you see LAN LED blinking immediately turn it OFF then wait three seconds, repeat, then power it on a third time and let it run.
Command line method to switch partitions:
ubootenv get boot_part
then set the opposite value
ubootenv set boot_part 1
ubootenv set boot_part 2
If flash upgrades from the DD-WRT web interface are unsuccessful, nor able to switch partitions to stock Linksys firmware, you will need to flash from command line via Telnet/SSH.
I wouldn't recommend Chrome for DD-WRT's web interface, nor Linksys.