I got ripped off on a dead Amiga 4000

[TjLaZer]

It looks like it got damaged in transit.  The listing and seller look legit.  The system is old so please try and be understanding.  You got a good deal for it and even the case is rare.  I would just keep it and buy another MB, IMHO!  It would be worth it.  Or you can send it off to Amiga Center in France to fix it.  Well worth it.  I know you are mad but this stuff happens especially for vintage computer gear.  The 4000 is not very stable to begin with.  I have had a few 4000's die out of the blue too.  I now have like 5 as backups! LOL

I would disassemble it down to the bare MB and reconnect the floppy, PS, memory chips and daughter board and CPU card and see if you get a KS boot screen (purple insert disk screen)  Give it about a minute for this screen to show up if there is no IDE device connected.

[TjLaZer]

In a perfect world I'd send my Amiga off to the good repair center in France but I just wrecked my vehicle again and was already broke before that.  If I can't fix it myself, it won't get fixed, and that'll be a tragedy.  Who cares about the seller by the way?  He got money for this and it doesn't work until I fix it.

My point is unfortunate things do happen and this is not the sellers fault.  (unless the packaging was bad and it came physically damaged)  Cards do come loose and most people don't think about the cards working loose.  It's an honest mistake.  The CPU card is not a PCI or Zorro card after all.  That High Flyer case and everything else is worth the money you paid so I would rather keep it all as is then send it back for a refund.  That's just me though...  If you had it insured you could try to get the money back, but I think there has to be PHYSICAL damage or else they won't give you money.

I had a 2000 shipped years ago and it arrived in pieces!  UPS issued me a check for the $600 I had it insured for.  It did take like 2 months but I finally did get the $ and I bought another NOS A2000.  

Good luck I know how you feel.