Hi
I got an N9912A which is a very early model (I think 2008). It could not boot because the front panel board was dead which I replaced with a board that I had bought (aimlessly) for parts long time ago for $40 even though I never thought I would need it one day
![Grin ;D](https://www.eevblog.com/forum/Smileys/default/grin.gif)
So anyways, the unit boots now with no errors and measures (both SA and VNA) and works fine except that RF board serial and part number/identity and SB serial and part numebr (whatever that means) show up as "?" in the system info page.
I noticed that two components (
U7 and U6) on the main board have been removed - see attached photo.
I am surprised that the unit does not complain...but I guess they must have something to do with the problem I just described
I have not tested the LAN and SD card but USB port works. So maybe those are not working either...
I cannot find any photo of this main board anywhere to figure out what those components must be. I am sure they are either some kind of voltage regulator or maybe a logic gate.
I was wondering if anyone has a similar main board or pictures of it that can help me to identify the two missing parts