the 7200 routers and up load up a little differently.
First go into rommon and change your confreg to 0x2101 and reset
rommon 1 > confreg 0x2101
rommon 2 > reset
If your boot image is valid you will come up in boot image mode, Then just set up an interface and copy an ios to flash from tftp. Change your config-reg back to 0x2102 and reload.
Router(boot)(config)#config-register 0x2102
If both the ios and boot image are corrupted, the only way to replace them is to put the pcmcia card into another router and copy the image from there. Or swap cards with another 7200 and try to boot from that.
Here is an excellent link for this:
http://www.cisco.com/en/US/products/hw/routers/ps359/products_tech_note09186a00800a750e.shtml#download
Good luck.
hth
BT