In my experience, once you switch the fuse settings to an external crystal, if there is a problem with the external crystal, then the processor will not communicate through an ICSP. Once the crystal issue was resolved everything worked. Your experience sounds similar to mine but not identical.Do you have anything connected to the board?
By "crystal" do you mean "crystal and capacitors"?
Please enter a valid email to subscribe
We need to confirm your email address.
To complete the subscription, please click the link in the
email we just sent you.
Thank you for subscribing!
via Egeo 16