No GPS Fix on my SIMRAD EV2

So that's the ESO box that would use a remote GPS antenna.
From that antenna, what is blocking the whole sky would be my first question?
Next, what work on the boat since it last worked?

Is it doing this even when boat is moving? When I turn on my Simrad units I sometimes get "No GPS Fix" at the dock. Once I start moving it usually locks on within a minute or two.

Have you checked the antenna cable for chaffing? Years ago I had intermittent issues with a garmin as the cable had been damaged where it went thru fiberglass

You are looking at the page that shows this? Zero sats or a few and not in the green yet.

There are tables, clock signals, updates and corrections sent from the sats to receivers consonantly.
These have to be loaded before the receiver can do anything. It may take several minutes for these updates to load and be installed.
If you have been powered off a while, your receiver may be in need of some of this.

Can you power it up and leave it on a hour or so?

From post #2; Is the whole or a large part of the sky available to the receiver?
It may take more than 1 sat to update your receiver with these updates.
Then it takes a few to begin to figure your location.

Another thought, Do you have an AIS transceiver? It it receiving GPS signals?

How old is the GPS receiver? Some brands have batteries that fail with age.

I have had an issue a handful of times requiring the GPS antenna to be restarted, requiring either a power cycle from a breaker or visiting the cable connecting it to the backbone and disconnecting. Does your GPS antenna have an indicator light on it showing function?

Check the network settings in the Simard to make sure it is configured to accept the GPS antenna data.

If the vessel's sole source of GPS data is the same GPS antenna that your Simrad is requiring, then you don't have a GPS data problem to the backbone given the AIS is obtaining and sharing a GPS signal. Just be certain the AIS doesn't have its own GPS?? Or see if you GPS is also showing up on your VHF or pilot controls? Then as mentioned, you're back to the Simrad, connectivity, and set up recognition of the GPS, to allow it to accept the GPS data signal from the backbone. You should have a setup page where this network data is visible on the Simrad...?

Yes, good plan. The problem may be as simple as a dead GPS. Ive replaced mine as well once...it happens. Best test for Simrad is if the GPS can connect directly to Simrad and eliminate other variables for this test.

If it is all Simrad, Your AIS antenna is passive and goes to the AIS box. The other GPS is active and goes to the N2K back bone.
In AIS setup, you can tell the AIS what to send to the N2K backbone. It is usually set to minimum info and AIS data only.
Also, I recall a setup in NSS that tells the equipment what GPS to use. You may want to double check in your NSO.

Any progress?