-edited for clarity-
Everything you need is right here in this post...no guesswork involved just RTFM

I circled the 3 pins where you connect to in red here:

Looking at the controller board straight on, the ground *should* be the pinhole on the far right, if not its far left (double check with voltmeter as I have no unit to test right now) the other 2 pinholes are tx/rx.
Once you confirm the ground (0v on voltmeter), then connect tx and rx....if you get a load of junk on your screen reverse the rx/tx and you will see magic...well not really but you will see the data on the screen...for putty set 115200, no flow control, and make sure you have the correct COM port defined (115200,8,n,1)
I posted a direct link where to get the cp2102 earlier (the tx thing)

http://www.dx.com/p/usb-to-uart-5-pin-cp2102-module-serial-converter-81872#.VI6YldJ0yUlThere is no bs ad commission or anything for that part; you can order it anywhere on the net..I provided the link where I got mine to make things easy (or so I thought)
In Short...you need the thing in the picture (link provided) putty for serial connection and 3 bogo pins (that's what the gold pins are called)
Alternately you can just use sewing pins and push the sharp end into the connector MacGyver style, just don't move anything once you have them connected

Once you have access to the miner, type
mtd -r erase rootfs_data and hit enter
then type
REBOOT and hit enter...then wait 3 minutes before accessing the default miner IP address...
do not power cycle the unit Last of all...don't hold me responsible if anything goes wrong...but if I helped, a thanks would be great

Sure fire fix assuming hardware is ok and uboot intact is uboot based recovery, interrupt the boot process and set your computers IP to a static IP of 192.168.1.100. Start a TFTP server on your computer serving antMiner_S320141013.bin and run the following commands on your miner.
tftpboot 0x80000000 antMiner_S320141013.bin
erase 0x9f020000 +0x7c0000
cp.b 0x80000000 0x9f020000 0x7c0000
bootm 0x9f020000
Just put the firmware bin file into the root directory on a tftp server running on 192.168.1.100 subnet mask 255.255.255.0 and execute the above commands from uboot to flash it.
Thanks for the output, I'll browse through and see if I can spot a light at the end of the tunnell.
By the way, I meant the command altogether, i.e:
run mtd -r erase rootfs_data
This won't work from uboot so don't bother trying it if thats as far as you can get.