JFS524E cannot access neither reset to factory default

Hi,
  I am trying to set up a ProSafe JFS524E (unmanaged plus) switch.

I don't have a dhcp server on my network, so I have connected my PC directly to the switch, set up IP as 192.168.0.210/24, disabled antivirus and firewall on the PC (winXP Pro Sp3, with admin rights).

Pinging 192.168.0.239 (which seems, according to [1], the IP address the switch falls back to if it doesn't obtain any from DHCP) I don't not obtain any answer.
I tried all of this also with another PC (linux), with the same result.

I am not able to manage the device through the UM+ Configuration Utility, because I can see the device is listed, it asks me for a password but regardless of the password (except I leave the password field blank, in which case the answer is "Password cannot be empty!") the answer is "Network error. Please ensure your link is up and retry!".

This happens with both UM+ config utility v1.2B20 (supplied on the CD that came with the device) and v2.5.3 (last version as stated in [2]). (With v2.5.3 I have a further problem, i.e. there is a "username" field to fill in, neither providing "Admin" nor leaving it blank works, but I am not sure which username is correct, and even whether the version 2.5.3. supports my device or not.)

I am trying to understand how to "factory reset" the device, but I am not sure to know which is the factory default reset button. It seems [3] that the hole in the front of the device is not the one I need to do the factory reset. Btw, I tried to use this front button:
- holding it pressed down for 30 seconds, while the device is turned on;
- pressing it with the device turned off, holding it pressed down while turning on the device, and holding it pressed down for another 30 seconds after the device turns on
...but the problem remains.

Another article [4] says that the default IP address is 192.168.1.1, but using this IP/subnet gives me the same results.

Many other links, articles or threads from this forum ([5], [6], [7], [8]) did not help me.

Could anybody help me please?

Thank you very much for your help and patience,
Andrea


[1]: https://kb.netgear.com/30418/What-is-the-default-IP-address-of-my-NETGEAR-Smart-Managed-Plus-Smart-Managed-Pro-or-Insight-Managed-Smart-Cloud-switch
[2]: https://www.netgear.it/support/product/JFS524E.aspx
[3]: https://kb.netgear.com/24679/How-do-I-reset-a-smart-switch-to-factory-default-settings
[4]: https://kb.netgear.com/6663/ProSAFE-Factory-reset-routers
[5]: https://community.netgear.com/t5/Managed-Switches/JGS524Ev2-Password-reset-assistance/td-p/1029765
[6]: https://kb.netgear.com/1148/What-are-the-default-web-interface-passwords-for-NETGEAR-devices
[7]: https://kb.netgear.com/31261/How-do-I-access-the-admin-page-of-my-ProSAFE-Web-Managed-Plus-or-Click-Switch
[8]: https://kb.netgear.com/12344/Unable-to-detect-the-ProSAFE-plus-switch-using-the-UM-utility