Netinstall fails on Groove a52 (no progress)

Hello! After rebooting groove a52 is not working properly. It doesn’t respond via ethernet and no wifi Ap. Now it just box with leds and beeper=). I did hardware reset - nothing changed. I tried to recover firmware via netinstall, but it doesn’t work - when i push button “install” there are no any progress - just permanent text label about formatting. And nothing happens…I tried versions 5.25, 6.18, 6.19 everywhere is same problem. I have no any firewall, antivirus etc. Windows 7 x64. I tried use even Win XP Live CD…
Sorry for my bad English=) Thanks

Look at this netinstall procedure on my website.
http://www.wirelessinfo.be/index.php/mikrotik/pages/netinstalle