The eBay Money Back Guarantee was voided the minute you opened the console up. You cannot attempt any repair or modification, even if it's just for diagnosis. You're not entitled to any refund or return.
I obviously didn't tell the seller I opened it, I admitted in this thread its unethical but again NO HARM NO FOUL. I took a few screws out, I removed some plastic - this does not damage the wifi board. I also verified that my other wifi board works fine in it! This only verifies the product is defective to start with.
It is unethical to open the 3DS for diagnosis and then demand a partial refund or return because doing so is a clear violation of the eBay MBG to which you agreed when you decided to buy the item. Even if you didn't read the terms, you're still bound by them.
If you had mentioned anywhere in eBay messages or in the case itself that you opened the item the seller should be able to get the case escalated and closed in his or her favor with some phone calls. That will also remove the feedback you left for him or her as well as any defects generated from the transaction. If you mentioned to them that you intended to leave negative feedback, they should also report you for feedback extortion.
You can't claim no harm no foul, either. Regardless of whether or not you return the item, you've damaged his or her account unnecessarily when you could have sorted the issue out through an exchange of messages, rather than via opening a case and negative feedback. If you sent your first message to the seller on Friday and got a response today, that makes it just one business day it took them to reply, since Saturday and Sunday don't count. So clearly they do read their messages.
While I agree it's lousy to receive an item that's not quite as described, you've got to play by the rules. Just treat sellers how you'd like to be treated yourself if you were in their position. It could be their livelihood, after all. I'm sure you wouldn't be happy if someone trashed your account over an honest mistake without giving you a chance to resolve it.
EDIT: Upon re-reading my post, I can see that Bug_Checker_ is right to call it flaming.
To VashTS, I owe you an apology. While you can confirm if you like that what I've said about the
eBay MBG and
feedback is accurate by reading the terms yourself, it was very wrong of me to say it all so harshly. My intention was only to inform you of the policies as well as the damage done to the seller's account, but I did so in a rude and judgmental way, which I sincerely regret and for which you deserve an apology.
