Question Why does my PC freeze when GPU is connected ?

[Disvsros]

I switched gpu from r9 390 to 1070 yesterday and the computer isn't working with any of these gpus right now.
Once I start the pc it freeze after about 20 seconds, I tried to reset the bios but it still isn't working.
When the gpu isn't plugged it's working without any problem, what can cause the issue?

 

[Phillip Corcoran]

Sounds like the PSU may be the problem (output too low for a GTX 1070, or it's simply a rubbish PSU model).

Post full system specs including PSU details.

 

[Disvsros]

OS: windows 10
CPU:i7 4790k
Motherboard: gigabyte z97-d3h
RAM:4x4 g.skill 1333mhz (dual channel) (2x4gb)
GPU: old gpu r9 390/new gpu nvidia 1070
HDD: evo860 500gb
psu:antec 750w eag pro

I tried to flash the bios already and tried to use another psu (600w) but it isnst help
update:now its crashing even without the gpu mounted

 

[Phillip Corcoran]

PSU has enough power and is certainly not a rubbish model, so I don't know what's causing your problem, unless PSU is faulty/old and not performing as it should.
Please wait for replies from other helpers as I don't want to be giving you bad advice by just guessing.