Please help, samsung rs21

Hi please help, ive just hade my samsung rs21 amercain f/f fitted with a new safty switch fitted because of the rick of fire to this modle, and a few other problems fixed aswell like rear fan and evarater cover, problem is when i came back from work next day the electy hade gone, when i turned it back on, the f/f are not getting cold, ive phoned the people up who reapired it and now the say the compiser might have gone, ive done the dionages there are no fault codes, my main problem is i bought the f/f second hand and very worried about the big bill from samsung,, is it normal for the comisper to pack up so soon after a safty check?, will i still be covered under the 5 year warrenty enen thow i got it seond hand? Im at mt wits end will the f/f, if im not covered how much will it cost to reapir? Thanks in advance