Have been having problems with maintaining connection so decided to pursue the upgrade. When I did the upgrade, I found that I could no longer access my tonidoplug2. My router can't identify the tonidoplug IP although doing the http://www.tonido.com/ip finds an previous IP using the MAC address approach. DHCP reset does nothing. SSH or pinging find nothing at that address.Unit won't boot from USBs built using the bootable USB directions. Just sits there with a blinking red light. Advice please.

If you open your router, you can't see the TonidoPlug in the list?
Have you tried restarting it?

You can try to use a network scanner to enumerate devices in the network.
http://www.softperfect.com/products/networkscanner/

Thank you. I've installed netscanner but it didn't find the tonidoplug2. I've tried using the DHCPnet and datacollector utilities but neither generates anything. So I've not been able to connect with the unit.
I've also built a bootable USB and SATA drive using rootfs.tar.gz - neither seems to be accepted. The only visual that I get is about 15 seconds after I plug in the USB stick, it responds by it's usual flashing. The USB stick booted my linux computer OK (I'm using LinuxMint).

It appears your plug is not responding any more or not connecting to the network. Please do check your ethernet cable if you haven't already.

If those all look fine, this might be a faulty unit and might need RMA/return.
The 2.5x upgrade can't really make the plug invisible on the network.

Please send an email to support@codelathe.com and mention this forum thread to start a RMA process.

Thank you. Will do.