I was running firmware 1.10.
Unfortunatelly, it seems my router has died forever....
I was looking around in the admin page then I tried to save the config to generate debug logs, but when I saved the config, I went into the blank screen again, but this time the router didn't boot up anymore, and went back to the unresponsive state.
I repeated the crash reset and could open the upload firmware page, but this time the upload doesn't work at all, the percentage value keeps raising until 100% but I could see from the PC netwok status that no packet was being sent to the router..... I repeated this several times but none of them was successful.... I could observe that after I ask the page to upload the firware, the status led stop blinking, and probably the firware receiver of the router stops responding....
This seems a hardware problem and apparentlly it happened without some good reason. This router was plugged in a no-break, so I think I can discard any power supply problems... I noticed it gets really hot when in use, so maybe some component may have burned with its continuous use, although this should not happen in good products....