I have a Cisco 837 before me and it's doing some very strange things. It's straight out of the box so is running the default config. The problem is this: when it's booting, the relevant interface lights on the front flicker reassuringly and all is well. When it finally starts up, the ATM tx/rx lights start flashing loads, won't stop, and the ethernet link lights go out and won't come back on.
All this with the unit not even connected to the ATM (DSL) circuit! I've tried giving the router a simple config but it doesn't make any difference. Can't ping anything from it, other than itself, and nothing can see it. I'm sure the flashing ATM lights are something to do with it but can't find a solution at the moment. Would appreciate any help that you might be able to give.