Question 970 to 1080ti swap issues

[AlmostGotItWorking]

So first off base system info:

No Overclocks on anything
MoBo: MSI Z170A
CPU: I7-6700k
PSU: Visiontek 800w
RAM: 16gb (4x4gb) DDR4 Ripjaw

Currently, I am running a GTX 970 in my system with no issues. However, I am thinking of purchasing a 1080ti strix from a friend and we swapped it into my pc to make sure it is viable. We then run into issues, first I had to get another 8pin pci-e cord since my 970 ran an 8pin - 6pin + 8pin and the new GPU uses two 8 pins. So get an 8 pin - 2x8 pin and plug it in. With the system off both LEDs (above the 8 pins on the GPU) are white, push the power button and the pc attempts to power on. The GPU and system light up for half a second then the 8 pin LED on the graphics card flashes red and the pc attempts to boot again after a slight delay. It is then stuck in this cycle until power is switched off.

Through some troubleshooting I pulled out an old psu (still good 620w Corsair) and used that to power just the gpu and the system then boots however I get no signal to my monitors. I have also powered on the pc with the 1080ti in and no pci-e power to it and this produces a message to my pc saying to connect pci-e power. A 3rd friend is also able to run the card no issues in his pc. So I am a bit confused, this seems to me to be a power issue but, 800w should be enough for my system no?

I'd really not like to order a new psu and rewire everything if this isn't necessary (psu is currently semi-mod).

Thanks in advance.

 

[MrN1ce9uy]

Good PSUs are a great investment. They protect your system by providing clean and efficient power, and the most important part of all is the warranty they provide if they do happen to fail. Your PSU is very likely out of warranty, and it wasn't a very good PSU to begin.

I'm not sure how you connected the Corsair PSU. Did you short the two pins on the 24-pin connector? Did you have a 24-pin splitter? If not, the Corsair was not able to provide any power without the 24-pin connector being shorted or connected to the system.

 

[AlmostGotItWorking]

I did not short the pins on the 24-pin...forgot about that. So therefore, my system boot (w/ the 1080ti) on 1 8 pin pci-e? Then why wouldn't it work on 2 8 pin pci-e? or is it that you are saying my issue is power related and you are surmising my psu is bad?

 

[MrN1ce9uy]

Get yourself a proper power supply. Neither of your power supplies are worth using with a 1080 Ti. They are old, outdated, and out of warranty.

 

[SgtScream]

Did the second additional psu power cable come with the visontek power supply?

 

[AlmostGotItWorking]

Update: Did some further testing and ended up ordering a new PSU as recommended. It seems to have been an amperage issue with the old psu rails. Thanks again for the help.

 

[DSzymborski]

Update: Did some further testing and ended up ordering a new PSU as recommended. It seems to have been an amperage issue with the old psu rails. Thanks again for the help.

Glad to hear. The old Topower-made PSU had some really dire capacitors in there. It's lucky it failed when it did and didn't take anything out with it - I would not have wanted to trust a high-end GPU with that thing.