Hello everybody. I recently bought a used msi gtx 780 ti gaming, so i could play recent games with good details. I planned to put the card on a exp gdc beast 8.5, which is a mpcie adapter that connects to your laptop and allows you to use an external graphics card. When i received the card, i put it in my slower desktop for a test. The card uses one 6 pin pcie and one 8 pin pcie power connectors. I plugged them in, but i plugged the 8 pin the other way around, without noticing, I had to force it, but I didn´t realize that at the moment. I powered the pc, but the pc did not turn on. I did it a couple of times, and then i realized the 8 pin was not plugged in correctly. When I received the exp adapter in the mail, i installed it, put the graphics card on it, powered the graphics card and the adapter ( cpu power connector and 21 pin power connector ) with the psu, and it booted up, i installed the drivers, and it worked. But when I run benchmarks, like combustor or so, os some more intensive games, on replays and such, it crashes with a black screen, but i can still hear the sound. I then used msi afterburner to lower the power limit to minimum, (57%) and it runs everything ok, even the benchmarks or games. I then unlocked the voltage control. and got to the max voltage of around 1000mv, with power limit to 100% and default clocks. With those settings, the benchmarks run ok. But if I put the voltage on auto it crashes. The power supply is 450w, 2 twelve volt rails of 15 and 16a each, 24 amps on 5, and 30 on 5v. I even bought another power supply, a 600w nox, with 2 twelve volt rails of around 21 amps each, making a total of 450w on the 12v rails, 24a on 5v, and 32a on 3v. With this power supply, i can only use lower max voltages of 900mv or so, with lower power limits. I have measured the voltage on 12v rail when the card is under load, and it´s very low, almost at 11.1v. One psu doesn´t shut down, but the nox one does. I suspect the card is putting a heavier load on the psu then it should. I have some knowledge in electronics, mostly analog, and i have a multimeter and some other tools. I dont know what is wrong with the card, i've looked at the 780ti pcb just to have an ideia of how everything is layed out. I apologize for the long post, but i tried to describe it as well as i could so it should be easier to troubleshoot. I came here, because I had seen some very good tech advice here some time ago, regarding a 780ti, and I thought I'd ask for some help. The card is a msi gtx 780 ti gaming, my pc is a toshiba laptop satellite l 850 1pd with a i7 3630qm and 4 gigs ram.
Any help is appreciated. Many thanks in advance.
cheers,
joao g.