How to clear corrupted NVRAM in 2507?

[paul3221]

Hi,
I've got a 2507 router that I was using to study for my CCNA. The other day, it kind of froze up, so I powered it off and back on. At that time, I received the following message:

Exception: Line 1111 Emulator at 0x110ED72 (PC)

I've tried different things to get it to boot, and the only one that works is repacing the old NVRAM chip. It will boot with that in. Unfortunately, it's only 4mb, and has IOS 10.x on it. Is there any way to erase the current NVRAM, so that I can tftp IOS 12.1 back onto it?

There are a few jumpers on the board, but I can't find anywhere what they do. I've also tried interrupting the boot process to change the configuration register, but no dice. It doesn't even get that far.

Any ideas would be greatly appreciated.

Thx,
Paul

 

[JOAMON]

Need to break the boot sequence and start in rommon mode. From rommon> you can delete it. Before you do that configure your router to boot IOS from tftp server. That way when no IOS on chip IOS will load from tftp, then you can flash with new image, change configuration register setting back, reload and should be good.