All bets are off once it leaves my place.
I am a hobbyist not a business and plus how can you give a warranty on something thats 20 , 30 or more years old that was designed to last for 5 yrs?
Having said that I have made a house call twice .
Once when I sold a game to a couple in their 50's who were buying their 1st pin , when it had a fault a couple of weeks after I sold it.
The other when a pin I sold turned up DOA at the other end of the trip from my place . Luckily both pins were close by.