problema en denon 2311 - dónde lo envío

Me he resistido a enviarlo, y he seguido con pruebas. Me he comprado el adaptador de usb-serial de belkin por si acaso y un cable nuevo (realmente no me está saliendo muy a cuenta lo de intentar probar de si es cosa del firmware). La cosa es que a 115200 que es como debería configurarse el com no funciona.

En los foros americanos he encontrado dos respuestas al problema, que saco mi versión pero nose si alguen sabra algo más de electronica/inglés , para ver si me aclaro: (pego por si alguien sabe, o por si alguien se encuentra con problema similar en el futuro que parece crónico de muchos modelos denon), (yo entiendo que deberia conectar el pin 1 y 5 manualmente con un cable o algo a la carcasa del conector o conectar un cable de carcasa de conector del receptor y la del ordenador):


"Why don't I get a serial port response?
RS-232C connections are sometimes overlooked as the cause of basic communication failure. The standard pins of 2=TxD, 3=RxD and 5 for signal common (S-GND) are used on our products. However pin 1 main ground (GND) is sometimes overlooked and may also need to be connected to the D-Sub 9's outer shield so that a complete main ground (GND) is established between the two products being connected. "

"What happens if an RS-232C cable run has been made, and after testing we can not communicate to the receiver?
The first thing to be done is to proof out the RS-232C cable to make sure it has been terminated properly to the correct pins on both ends and that there is continuity on all wire leads. If this proofs out good, then in place of running a new full pin to pin DB-9 cable, try a chassis ground wire connection from the chassis of the Denon equipment to the chassis of the control unit module, where the DB-9 cable is connected from the Denon unit. Most of the time, this will correct the problem and stop you from running a new line. If this corrects the problem, it would be suggested that a tag be put on the ground wire stating that it's a required wire for the control system to work for future reference."

Por si alguien con Denon le interesa aparte, que me parecio curioso, hay rulando por ahi manuales de comandos de telnet para interactuar/configurar por rs232 el denon a través de ordenador (de momento se me escapa, a ver si consigo primero simplemente conectar bien el cable )