I sold someone a brand new cpu (amd 4200+) about a week ago and he has bought a new motherboard(MSI K9N2GM) for it however upon installing said items his computer gives no display and a series of bios beeps (two and then six) now being familiar with the K6 K7 motherboards i seem to remember this problem not being the cpu, in fact when i had a similar problem with a "six beeper" in the k7 i seem to remember i had (rather nuubishly) not put my memory back in probably. Now my mate is claiming the problem is my unused cpu and claiming i need to pay him back by saying it cant be anything else. Do i need to pay him back? or was it his hardware? And if i do i need a cheap cpu for a K9 (as above any suggestions?really just need confirmation in writing seeing as he wont believe me pulled up the posts on AMI bios and still my fault, ive EVEN tried telling him that if the cpu is dead the bios cant start to beep but at the minute everything i do or say is wrong

If he INSTALLED it i can't say as your liable...however i know how mates can get when it comes to money.
Unless you know the BIOS for his MSI board it can't be generalised that your beep code experience means the same as what he is having...
What other components has he put into this build..;.I.E. is the RAM new or USED ?...Where was the board purchased ? ?
All i'm saying is it could be the CPU but on the other hand it could be 8 or so other things as well...Sounds like a case of Caveat_emptor, darkmajicks.

Personally if I were to sell anything to someone else, I would say thank you goodbye.

Once an item has left your possession and you no longer have an active control over what is done to it, or how it is handled, stored, transported or used, ( and any other description you could think of) the liability of its ability to perform in the required task is released from yourself and the new owner is responsible for the safe handling etc. of his new purchase.

Your friend might profess to have handled it with the expertise of a museum caretaker USING kid gloves and nurtured its every movement. All something you have absolutely no information of, nor could reasonably confirm.

On the other hand he might have thrown it in the passenger seat of the car, driven down a bumpy dirt road where it fell to the floor of his 1979 mustang convertable and was tossed around clanging into metal objects and pizza remains. Then on exiting the car, HIS new unit in hand, slipped on the wet road and dropped HIS new purchase in a puddle of water, rendering it inoperable.

I found this, here , it  may have have some jewel of insight to help you.

The views and thoughts of ImnoGuru are in no way to be construed as legal advice on this or any issue, nor are they to be used as foundation for any argument or dispute between two or more parties.If it helps anyone out there its ami bios beep codes and its two followed by six

Here you go....

http://www.msicomputer.com/support/sup_tshoot.asp

I think you may find some info on that site....

http://www.pchell.com/hardware/beepcodes.shtml#ami

Or this one......