Mystery GPU shutdowns

[nickf23]

Morning all . Need advice .
I have a full custom water loop on my PC . Started to get GPU errors when gaming , games would freeze , sound would fail and sometimes PC would crash off . Stripped system , sent MOBO and CPU back to supplier as tests on test bench seemed to point to these being an issue . Both were replaced . Rebuilt PC on test bench with GPU now back with its original FE blower cooler . Everything ran without issue , had spare GPU ( both GTX1080 FE ) This was the same ran with no issues , even tried different MOBO ,RAM and PSU , all worked just fine . Rebuilt PC with water loop , ran fine for about 2 hrs then started doind as before ?! . Fit different water block to other GPU and swapped out . Ran ok for 1 HR , problems started again , PC freezes or shutsdown . They only differences with test bench are number of fans and obviously the water pump , and also 1 HDD . PSU is an EVGA 850 P2 . I am thinking that maybe , just maybe the PSU is failing , as this is the only part not changed whilst on water , I do have an EVGA 650 P2 to try , but any helpful advice would be gratefully received

 

[nickf23]

Thanks guys , I will wire my 650W PSU just to GPU this evening

 

[nickf23]

Yea , tried the obvious, but always worth reminding , it's so easy to miss the simple stuff . Tried different cables , different slots and even tried with and without riser cable . Just got home , so I am going to check the basic stuff again and wire in my other PSU .

 

[nickf23]

Well just an update . I ran all components 1m by one on my test bench , then all together . All stable . Tried different PSU , no change still did shutdowns . Replaced all cabling , got some extensions from CableMod ( look really Nice ) , been running for 7 days , so far no issues .