Question Need Help Troubleshooting NVS 420 Graphics Card Issues in HP Z420 Workstation


Jul 4, 2014
Hope someone here can help me with this. But I am in the process of setting up my HP z420 Workstation desktop to support 4 monitors for some day trading of stocks. The specs on my HP z420 desktop are that it has 32GB of RAM, an Intel Xeon E5-1650 CPU @ 3.2GHz, an Nvidia Quadro K600 graphics card, a DPS-600UB power supply, and a 240GB HP Enterprise SSD.

I was trying to add an NVS 420 graphics card since that graphics card can support 4 monitors by itself when you use it with an Amphenol 4 way DVI splitter. I believe that graphics card can support 4 monitors at 1920x1080 resolution with no problems. Anyways, I bought all my parts used on eBay. The PC works great with just the original K600 graphics card in it, but when I removed the K600 graphics card and installed the NVS 420 in its place my PC would not boot and would beep and give me a blinking red light. I thought maybe I didn't seat the NVS 420 properly so I removed and reinstalled and got the same issue. I then placed my old K600 back in there and the PC worked fine.

I then decided to add the NVS 420 to another slot and keep the K600 in there as well. The PC woud boot that way and recognized I had two graphics cards; both the K600 and NVS 420 installed and seemed to work fine. I was running 3 monitors off the NVS 420 and 1 monitor off the K600 and it seemed to be working fine. I noticed I could move the mouse between all 4 screens without lag. But if I moved a window from one monitor to another, there was a lot of lag and delay. I also noticed that if I surfed the internet on a monitor that was attached to the NVS 420 that it seemed a bit delayed also. I then noticed that the NVS 420's fan would not spin much at all. It would spin a bit, but never seemed to reach full speed and would then stop spinning. Kind of like someone was kicking the fan on and immediately turning the fan off. Then the PC froze and I had to turn the PC off and turn it back on. And the same thing happend again, after running the PC for like 5 to 15 minutes, it would freeze again. I then just felt that the NVS 420 was overheating due to a fan issue so I removed it completely and just left the K600 in there. With the K600 in there, the PC works great. Also, when I removed the NVS 420 it was pretty hot to the point where I had to be careful not to burn myself. Don't know if that's normal or not. The longest I ever ran the NVS 420 was probably around 15 minutes before my PC would freeze. I'm going to order a second used NVS 420 to see if that solves the issue since I think it would be unlikely that I get two bad NVS 420s.

My question is do you think the NVS 420 that I bought pre-owned on eBay just has a hardware issue since the fan doesn't seem to spin enough? Or is the NVS 420 not compatible with my HP z420 somehow? I didn't see any spots on the NVS 420 where it needs an extra power cable like some other graphics cards, so I just installed it by putting it directly into the graphics card slot and that's it. Is there something I am doing wrong or missing here? I'm not 100% positive what the problem is. Thanks