I agree with others that it would be wrong to use a scan as if that is the exact chip being offered - the words "representative scan" or "stock photo" or something similar should be used. When eBay injects a stock photo (based on pre-filled info for books, records, etc.), it says so. If you brought this to their attention, and someone actually read your complaint, they should be receptive to your argument.

Trademark law doesn't enter into it because you cannot obtain the trademark for the chip - the owner of the logos used on the chip have the trademark. You do not have a "trademark" in a photo - trademark applies to logos, names & phrases, color combinations, etc.

The related field of copyright law is not so clear. A photographer normally has a copyright in a photo. Even copyrighted materials can be used by others under certain circumstances, such as parody and "fair use" for educational and similar purposes. Putting something on the internet should not constitute waiver of the copyright any more than publishing it in a newspaper or posting it in an art gallery.

Scans, though, are not necessarily the same as photos. I haven't looked too deeply into this (my copyright experience as a lawyer predated the Internet), but a scan is like a photocopy - it is not necessarily an artistic impression of something (it is not an "original work"). IF ANY OTHER LAWYERS HAVE LOOKED INTO THE LEGAL DIFFERENCES BETWEEN SCANS AND PHOTOS, I'D LIKE TO HEAR FROM YOU.

If a copyright exists in your scan, you would have an easier time persuading eBay to pull it. Copyrighted material does not have to be registered with the copyright office. The author of an original work always has a copyright by operation of law.

Registering a copyright, though, has certain benefits. First, it provides presumptive ownership as of the registration date. Moreover, it entitles a copyright owner to automatic damages ($50,000 last I knew) if infringement is shown.

Without registration, you must show "actual damages" - usually meaning you must show the profit you lost or the profit the other party gained from the infringement. In the vast majority of cases, the damages are low or nil.