How Do I Check if a Second Hand Xbox Has That Ring of Death, I'm Buying off Someone in the Local Paper?

would it be obvious if it's faulty? how long would it take to find out, do many x boxes have this problem?

Suggestion:

yer get em to show u it working if it has the ring of death the lights round the power button will be red instead of green never buy Electric items of people you don't know with out checking if fully 1st

http://www.google.co.uk/imgres?imgurl=http://www.gadgetlite.com/wp-content/uploads/2010/06/red-xbox.jpg&imgrefurl=http://www.gadgetlite.com/2010/06/18/red-ring-death-xbox-360-slim/&h=390&w=450&sz=12&tbnid=nDELQgJGZPfwwM:&tbnh=110&tbnw=127&prev=/images%3Fq%3Dring%2Bof%2Bdeath%2Bxbox%2B360&zoom=1&q=ring+of+death+xbox+360&hl=en&usg=__lmjQODlVNVWn4gQElXUMBpfaIlY=&sa=X&ei=0IapTMibKMjKjAf_6LW8DA&ved=0CCwQ9QEwBQ

http://www.google.co.uk/imgres?imgurl=http://www.product-reviews.net/wp-content/userimages/2007/09/xbox-360-death.jpg&imgrefurl=http://www.product-reviews.net/2007/09/19/today-my-microsoft-xbox-360-has-red-ring-of-death-glad-own-sony-ps3-nintendo-wii/&usg=__MLyASTUajiVucIh2n_W4uYn_BTw=&h=270&w=609&sz=21&hl=en&start=0&zoom=1&tbnid=j43KGmw8YIBIKM:&tbnh=47&tbnw=105&prev=/images%3Fq%3Dring%2Bof%2Bdeath%2Bxbox%2B360%26um%3D1%26hl%3Den%26sa%3DX%26biw%3D1077%26bih%3D446%26tbs%3Disch:1&um=1&itbs=1&iact=rc&dur=406&ei=_oapTMLjHtGKswab5-jGDA&oei=_oapTMLjHtGKswab5-jGDA&esq=1&page=1&ndsp=17&ved=1t:429,r:5,s:0&tx=37&ty=20