The vagom is saying I have a short to ground and until I get another unit to plug into my car and see I can't be sure but anyway the cause was when I put dynamat in and the 2 pointy bits where wires connect to mid range in front right door touched the foil and have have no sound in that door since. If I reset fault and close radio controller quickly the speakers come alive for about 2 sec then cut out. Not to worry, it's only money. Might buy another one from tommy.
I have VCDS saying I've got 'shorts to ground' from certain speakers, but that's cause they're rewired. HU's can generate such a large output that I'd need several massive resistors, which get very hot I might add, behind the dash. I have no intention of fixing that.
My point is, VCDS saying there are 'shorts to ground' doesn't mean there's a problem with the RNS-510.
You do realise if you have any issues with the unit you might have a hard time proving you didn't cause it by opening the unit and voiding the warranty. Personal experience makes me think these units can be pretty twitchy.
Might be a great way to learn, but it's expensive if you stuff it up. How do you think you could have stuffed the internals of the RNS-510? Did you drop it?