Spectrum Analyzer Agilent E4408B - Worth buying for Repair?

[SaabFAN]

I found a Agilent E4408B online that doesn't respond to signals anymore, but otherwise seems to be working - At least there are no error-messages.
I'm guessing that the 1st Mixer is damaged and doesn't work anymore.
Does anyone know if the Mixer in these devices is actually repairable or can be replaced by something from minicircuits?
I don't need the full bandwidth up to 26GHz. The lower band up to 3GHz or so would be enough for the time being.

What else could have died?
On the pictures it looks like the noise-level increases with frequency - So the attenuator is definitely also a suspect.

[SaabFAN]

Has anyone taken a look at the Mixer of these devices?
Unfortunately, I haven't found anything on the web so far.

How vulnerable are these Mixers btw. and are there any other known failure points?

[ap]

The problem with these is that the special parts, if failed, are extremely expensive. There are quite a few of them with no replacement other than original. Even used, if you get one, they are expensive. Also, there are a couple of metal-enclosed PCBs, at least one of which is very hard to access internally and mesaure (plus, they also have several custom parts; you cannot even buy them from keysight). So its a major gamble. Older Agilent analyzers (8562 or 8563 e.g.) are easier to repair because much more used spare parts are available at reasonable prices. Plus, you have to have the right test gear to do the measurements (no chance if you don't)

[SaabFAN]

Ok, that's not so good, I also noted the seller has put up some new pictures with the following messages on screen:
"System Alignment - Align Nov. All required"
"LO Unlock"
"LO Unlevel"

Seems to me at least to be a similar error that was once shown and fixed on the "The Signal Path"-Channel on Youtube. So there might be hope that it is fixable without buying some expensive replacement parts.

Edit: Further research suggests that this failure is due to an error during construction of the ESA-E and ESA-L Series that was corrected sometime during the production cycle of the instruments.
There's a service bulletin available that deals with this exact problem.

[ap]

These had problems, several, but I did not find this one. The LO path has so many custom parts that I still think one would have to be very very lucky to fix it.

[SaabFAN]

Well, good luck to the winner of the auction then, who paid over 1700€
Hint: Wasn't me^^