why the 1841 router can't enter the IOS?

[tinajunjun]

when I start the router , I can't enter the IOS , and it enther the ROMMON mode , the error display probably is : the flash is invalid.
I want to import an new IOS into the flash, but it says the space is not enough.
how I confirm the flash is broken?
It's any other ways to solve this problem except to change the flash?

[Peter Paluch · Accepted solution]

Hi,

According to you description it seems that the Compact Flash (CF) card is faulty. Could you please post here the entire transcript of your router booting and ultimately falling back to ROMMON so that we can see the exact output?

In any case, there are numerous cases of the CF card in 1800 and 2800 series routers failing. I am afraid that the same happened to you. In any case, in a 1841 router, any commonly available CF card with a size up to 1GB (not necessarily Cisco genuine) would work.

Best regards,

Peter

[tinajunjun]

Thank you for your reply !

Sorry but I don't have the boot imformation.

And the 1841 router is already return to the client .

Thank you all the same !

If I have any problem in my work afterwards , I still need your help .......