Confirm the model
A familiar name can cover different internal parts. Steam Deck LCD and OLED components differ; ThinkPad T14 Gen 5 battery service depends on configuration; an iPhone 15 manual does not cover a 15 Pro. Ask for the model number or system information and match it with the maker’s parts and service page. Avoid posting a full serial number in a public listing.
Test likely wear points
Try the functions you would use: charge and unplug a laptop, play both headphone channels, dock a console, run a vacuum in normal mode or complete an appliance cycle where safe. One successful boot proves little about a battery, port, hinge, filter or seal. Ask which parts have been replaced and whether the work is documented. A damaged component needs a real local repair estimate, not a guessed part price.
Check access and total cost
Phones, laptops and consoles can remain tied to someone else’s account. Reach the normal setup screen after the seller removes locks before paying. For storage, agree on whether the original drive is included and erased. Add any needed repair, missing accessory or transport cost to the asking price; if the seller will not allow a safe basic test, value the product as unverified.