Before running the utility, unplug the power cable first. Then hold the hard reset button and plug the power cable back. Hopefully the device will blink the DIAG LED. If that happens, you could set a static IP, e.g. 192.168.1.100/255.255.255.0 on your PC and run the TFTP utility.
Unfortunately it turned out, that it would have been a really great advance, if I had just one win-box hangin' around here, to run this app. Because using wine to run it gave me just the ability to connect the router via TFTP. Even though it was a fine feeling, to see that the router is still alive and responding as expected in this situation by telling the TFTP-tool that it's firmware is corrupted, the tool was not able to fullfil this request. After doing something, it finally decided it might be better to hang up.
Fortunately my simple work-around I tried, worked fine. I just tried to access the built-in webfrontend of the router after establishing a connection via TFTP-tool.
And to be honest, I didn't expect that to work, 'cause the webfrontend was inaccessible before. But for any reason, it did.
Maybe establishing the TFTP connection forced it, to go back to work and do it's job like it was used to do all the time before.
Anyway. My router is up and running again and my weekend, along with some money is saved too.
Configure DHCP WAN Settings on the RV34x Router
A Wide Area Network (WAN) is a network that covers a broad area. A user or network of users can connect to the Internet through an Internet Service Provider (ISP) who offer...
Configure Static IP WAN Settings on the RV34x Router
A Wide Area Network (WAN) is a network that covers a broad area. A user or network of users can connect to the Internet through an Internet Service Provider (ISP) who ...