powerconnect 3548p - inactive console port

Dear Community,
I recently received a 3548p secondhand switch. Don't know if there's any telnet/ssh access configured, so I want to use a console connection. Unfortunately the only thing I get from my terminal is a black screen, no output whatsoever.
I use a db9-db9 cable (wired according to this article: https://www.dell.com/support/article/us/en/04/qna43618/what-type-of-console-cables-are-used-for-dell-powerconnect-n-series-and-force10-switches?lang=en) together with a com2usb converter (through which I connect to my 55xxs, 54xxs with no problem).
As for terminal software: I tried putty, kitty, realterm, termite and advanced serial port terminal. Terminal settings: 9600 baud, 8 data bits, 1 stop bit, no parity, no flow control.
Do you have any suggestions on what may be wrong or what other way may lead me to connect to the switch?
I would really appreciate your help.
Grzegorz