For an old V16.90 system, You should be connected to a "single" TTY "0" cable. The later Option 11e & 11c versions had a three way / port TTY cable outlet.
Make sure that the baud rate dip switch's on the CPU are set correctly. Move them all over to the left & then move over just one switch to your required baud rate.
You may well need to have a null modem adapter in line with your P.C.
Your Meridian will be slow to power up, But your first message should be a "HWRxxx" followed by data telling you which data storage is being used to load into the memory (usually taken from the Cartridge).
Make sure that you have CAPS LOCK on. For the older Meridians, I seem to remember that TTY's 1 & 2 were connected to the DTR / XTD card on a different cable.
I don't think that any power up details are displayed & anyway the baud rate is set with the Meridian programming.
All the best
Firebird Scrambler
Meridian Programmer in the UK