I have to disagree with the above two responses. According to Audiogon policy, the buyer's money should be refunded before the amp is returned.
The process should work exactly the same, except in reverse. The seller is not expected to ship the item until payment is received, and the buyer is not expected to return the item until the refund is received. The buyer is expected to cooperate with the seller to make arrangements for the shipping company to inspect for any damage, for insurance claims.
This is from the Audiogon Shipping Tips:
Generally speaking, the Seller is expected to refund to the buyer, and
recover the money by pursuing the damage claim. Shipping companies
generally pay the seller only and it may take some time. The Buyer
should not have to wait until the claim is processed. Essentially, it is
the Seller's responsibility to deliver the item to the buyer in an
undamaged condition.
Note: The word 'Generally' is used because occasionally the buyer directly pays for the shipping and insurance. In this case, the buyer should ship the amp back and process the insurance claim, since the insurance claim will only be paid to the person who purchased the insurance (normally the seller).
Here is a link to the page. Good luck, hopefully his lack of reply means the amp is working fine now.
http://support.audiogon.com/customer/portal/articles/227711-shipping-tips Cheers,
John