Does anyone have a schematic for these things so I can have a look and find the problems with them?
While the component-level schematics are not available, there is a quite comprehensive repair service guide for your instruments. This guide includes detailed block diagrams of each PCB in the device.
As for your calibration issues, I found a section in the "Interpreting Analyzer Messages" chapter for each of the two errors you mentioned. Both happen to be on page 626 and give some troubleshooting hints. Since both errors have to do with the A7 analog interface, that might be a good place to start. The description of this board's functions are on page 363.
If you wish to send them in for repair, extended service through Keysight is available for your product. You can find it by clicking on the “View Service Options” link in the “Product Status” status area for your product.
Hope this helps.
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