Hello all!
My father (a ham, like me) was recently given an Agilent E4402B by a fellow radio enthusiast. We're not sure where this guy got it, but he likely never turned it on - he's apparently a receiver guy and had no interest in a spectrum analyzer. My father and I, on the other hand, were incredibly excited to have such a piece of gear. All we knew about it is that "it might not work". Despite "only" being the 3GHz model, it seems to be well equipped - RF out, the 1D5 high-stability frequency reference, and a couple of cards I don't recognize. It has 16MB RAM and 32MB flash, too. Surprisingly few hours, too, 175 - at least 15-20 of us were from us fiddling around with it. It's pretty grody though, lots of what looks like mold under the display plexiglass. It has a sticker on the back suggesting the battery was replaced in Nov 2013, and it retains time & date, so that's still working. It even still has the original yellow floppy drive protector!
Upon powering on, it seems to pass all the software/digital self tests, but it fails to do an Align All because of the infamous LO Unlock error. It fails to display any signal at all, but we do know that the 10Mhz out on the back is good. I've done some research on this error, and I know that it could represent a lot of things, so I'm not really sure where to start. I have repaired and calibrated older analog scopes and frequency generators before, but nothing anywhere near this advanced. I watched Hugoneus' amazing 2 hour troubleshooting and repair video, and while I learned a lot, and could definitely do the repair he did, I unfortunately do not have the equipment needed to do the troubleshooting that he did (namely, a >3GHz scope, frequency counter, signal generator, etc.)
Additionally, I have read that if these ESA's get >0V put to their RF input, that'll completely blow out the front end, but I don't know if that's something that can be repaired - and I don't really know where to start as far as troubleshooting this. Like I said, we're both in over our heads here. While we probably could part it out or sell it as-is, we would like to at least take an honest stab at fixing it, if we can do so without making things significantly worse.
I guess what I came here looking for is some kind advice? He lives in the Raleigh, NC area, so right now my hope is to hook him up with a Makerspace, or someone with gear sufficient to begin properly troubleshooting and testing this thing, and see if we can get it ticking again. He's a mostly-homebrew, all QRP, radio operator, and a working spectrum analyzer would be something he could really benefit from.
I've uploaded a few pictures here if you want to check it out:
https://photos.millerjs.org/?f=Agilent+E4402BThanks all,
John KC1QLN & Kevin KI4DEF