Agilent Keysight N9320B missing internal drive

[analogRF]

I just got this N9320B in an auction (supposedly came from a university) that does not boot properly. It gets stuck at the Keysight splash screen (after passing the Agilent splash screen)
I opened it up and I noticed that there is an internal memory that is missing. It is actually removable from the back of instrument like hard drives but it does not seem to be a hard drive. It is not deep enough for a 2.5" hard drive to fit and the connector is male (see pics)

I cannot find any mention of this piece anywhere in the datasheet, user guide, or even the service guide that a friend gave me.
I don;t know if it is just an option that never existed or is it essential for booting the system. Does the firmware sit on this?
Also what type of memory could it be, is it some kind of compact flash or ssd ?

any suggestions on how to proceed? 

[coromonadalix]

this slot   is the gpib interface option ...

seen on this page  photos and the options ...   for the boot problems,  you may have some hints too ??

https://www.keysight.com/en/pdx-x201742-pn-N9320B/rf-spectrum-analyzer-bsa-9-khz-to-3-ghz?cc=US&lc=eng


configuration guide
https://literature.cdn.keysight.com/litweb/pdf/5990-8120EN.pdf


and finally  another thread here

https://www.eevblog.com/forum/testgear/spectrum-analyser-virus/

[analogRF]

ahh! yes, of course it must be the GPIB option  stupid me 

so my quest for solving the boot issue goes on...

I unpacked the firmware file and it seems to be based on vxworks.... I need to find out a serial console/interface to see what is going on, am I right?

[analogRF]

there is a DS1390U RTC with SPI interface on the board, do you think I can connect the RX/TX lines to a serial to USB converter and get a serial console to see the boot process?