I have purchased both a 950 ftw and a 750 ti ftw from evga. The 750 was doing great but I had enough for a 950 after a year and my brother needed a graphics card. So I bought the 950 and it was working fine at first but my brother took it out to test something. When I got it back from him my computer would not post. But the 750 worked fine. I got the 950 tested in the shop and it worked fine. But it still wont work in my pc but the 750 does. all drivers are up to date btw. And the mobo makes 2 short beeps with the 950 in but not with 750.
Any help would be appreciated

 

Try reflashing the latest motherboard bios to see if it helps fix the issue.

thing is you said it was working fine on the bios you all ready had ,so ? 
 
''So I bought the 950 and it was working fine at first but my brother took it out to test something.'''
 
don't show 2 beeps  as a code ??
 
https://www.manualslib.com/manual/553498/Dell-Xps-720-H2c.html?page=114#manual
 
I'd find out exactly  what your brother did  -  may try to clear cmos   then try to bot with the 900 card   in it after this -    if all else fails then try what sajin said  ?   thing is you know for sure it was working fully on your bios you have all ready  ???
 
you know when it comes to buddies and family  ''no good deed goes unpunished '' 

cant say ?  I pull cards a lot for things like cleaning and maybe a card swap  to check something [NVidia to amd  back to NVidia what ever and  so on ]  but   ??....   thing is  I would uninstall the driver  using the working card   and get things back down to windows default standard  vga driver   [fail safe driver built in to windows OS]    then remove the working card  - clear cmos   -   put the 950 back in and boot   -
 
now at that point you should get at least display for like entering the bios  screen  [ matter of fact should all ways get that anyway ]  if not ??    to me if it worked once should work 100 times just the same if nothing changed out side of the card  ..
 
I guess you rechecked the card was properly seated in the slot and any psu power leads were properly plugged in  and seated firmly to insure they all got good contact/ connections ??
 
to be honest being a dell  and how they are  I am surprised  the 900 card worked at all with out the latest bios and if the bios is updated enough to support any newer cards over a 600 series anyway 
 
like there xps 8700  would not support any newer cards w until dell released the A-10 bios  that gave it support for the 900 series   
 
I like this part  maybe like your experiencing ??
 
''   Just to emphasize if it's isn't clear -- the 970 does work perfectly that first time that it does boot.  No crashes, great 3D performance.  You just can't boot again without physically taking it out, booting, putting it back in.''
http://en.community.dell.com/support-forums/desktop/f/3515/t/19601491
 
so your dealing with dell   and looks like you may need them to give you a good new bios for newer cards  ?

I have an XPS 720 h2c. Will the xps 8700 a10 bios update work with it? Thanks again.
 
 

Ok I will just upgrade to A06 and I will post if it works. 
Thanks.
 

That's very strange, but I was planning to build a system in about 3 months which I will be putting the 950 in. I just wanted to make sure that it wasn't the 950 ftw that was broken. Now that I know it's just my system is too old I will just use the 750ti till I make new the system. I was a tech noobie back then when I bought the 950 and I didn't know the 950 would not work, I thought it was just plug and play like the 750. And A06 didn't work unsurprisingly.  Thank you, really I appreciate you helping me. 
 
Thanks, Budgetgamer111
                                                                                                                                    
                                                                                                                                                                                                                                                                   

I think they got lazy on the card v-bios   like I say google z68 with  gtx 970  and read up  on all involved  what worked and did not     there were some boards guys found they were 100% SOL   some worked  out of the box  some a evga card did not work but a MSI card would   , crazy...  then if you look most used a sandybridge  as well    then like you see some boards if you had a sandy they foot noted the newer bios  not to use them if you don't have a ive  ? so?? 
 
I guess like this one  ?
 
''* MSI recommend you to update BIOS with ME8 only if you are using IvyBridge 22nm CPU.
* There is no way to reflash back to ME7 if you already updated to ME8.
 
https://www.msi.com/Motherboard/support/Z68AG43_G3.html#down-bios
 
I guess its own risk to try to use them if a later bios was needed for any new card support and you had a sandy ??     all I know was a lot of guys fighting a 900 card in to make them work 
 
good luck