mcp200 w/continual problems

The only way to check it is to replace the cable.

I'll have it work fine for days on end, and then it just goes wonky for several more days.
It is baffling.

The shop can just run the cable from the antenna to the box along the outside - no need to replace the original routing of the cable to check it.
And even then, when my cable was replaced, they routed it along the outside and then under the floor to the box. They did not tear up the interior to route it the same way.

My current problems with this current unit have nothing to do with the cable itself, as far as I can tell.
Trouble is, they are not replaced by a new unit. It is refurbished, whatever that means. I think it means they reinstall the software and call it good to go for the next poor soul to get it.

It could be a faulty memory module. But I'd bet that it is soldered in, and no one in the process of 'refurbishing' knows how to replace it correctly - possibly even to test for it.