Anritsu MS420K VNA help

[cincin]

Beginner here!
I recently acquired an older VNA, as-is, an Anritsu MS420K, and I could use some help in testing it, and considering potential repairs.

It appears to be functional, but I suspect the inputs are blown... but I could be wrong.

It powers on, does the warming up period, does the calibration, then shows the trace and does the sweep.
It responds to controls and adjustments.
The synthesizer appears to be working, I see a clean sine sweep coming out of the output.

But the trace does not change when I connect the synthesizer output to either input T or R.
This suggest that either the input is blown, or the bare port sans-signal has the same response as the co-ax cable with the sweep...
BUT if I set the input range too low, the Overload lights do light up, so the overload circuit at least is seeing the synth signal.

I have been reading the user manual for this VNA, and studying what it all means, but the Performance Test (section 6), the part I need, is missing.

- Does anyone have the Performance Test section of the user manual?

All insights appreciated! Thanks