Question Zotac GTX 1660 not working with B450 Aorus Elite

[itm]

I've upgraded my Windows 10 system with a new Zotac GTX 1660 display card and B450 Aorus Elite motherboard. At first everything worked fine. Then I installed an M.2 NVMe SSD in the PCIe slot next to the card that the Zotac was installed in, and since then the Zotac card has not been functioning - I get no video signal at all. If I replace the Zotac with my old Asus GTX 550 TI (in the same slot) everything is fine.
I'm using a Displayport-VGA adapter to connect to my monitor, so thought that might be causing the problem, so I switched to an HDMI connection. This time there was a blue pattern displayed on the monitor briefly, a minute or so after booting, but other than that nothing at all.
Any ideas for how I can diagnose the problem with the Zotac adapter?

 

[rgd1101]

full system spec? include make and model of the psu

 

[itm]

Ryzen 2700X CPU
Zotac GTX 1660 graphics
B450 Aorus Elite motherboard
32GB Corsair Vengeance LPX DDR4 3200MHz Memory
WD Blue SN550 PCIe NVMe SSD 1TB
Corsair CX600 PSU
Samsung 3TB HDD
Hitachi 500GB HDD

 

[itm]

So I swapped the GTX 1660 back in and now the HDMI output seems to work - I can display output to a monitor. Still nothing from the displayport output though - it's connected to a 2nd monitor using a Displayport-VGA adapter. Windows does not detect a 2nd display.
I've ordered another (different vendor) Displayport-VGA adapter for delivery tomorrow - hopefully that will tell me whether the problem is with the adapter or with the GTX 1660

 

[rgd1101]

dp to vga? need an active adapter

 

[itm]

Not sure what you mean by an "active adapter". As I said, the Displayport-VGA adapter was working fine until I installed the M.2 PCIe SSD.
I've just ordered a different one for delivery tomorrow:
https://www.amazon.co.uk/gp/product/B00Z08TZNU/ref=ppx_yo_dt_b_asin_title_o00_s01?ie=UTF8&psc=1
Would you expect this to work?

 

[logainofhades]

Try a CMOS reset. Sometimes the bios gets a bit confused, when adding, and removing hardware.

 

[itm]

I just got a Displayport to HDMI cable in the post, and have plugged that into the Zotac. So now the HDMI port on the Zotac is connected to my main monitor, and the Displayport is connected to a TV. When I boot I don't see the BIOS screen on either of the two displays. It used to display on my main monitor when that was the only display connected (via HDMI). Both displays work fine once Windows 10 has booted.
So it seems that the Displayport on the Zotac is not faulty, but if I use it I lose the ability to get to the POST/BIOS screens, which is a bit of a problem.
Any ideas for how I can fix this?
I haven't tried a CMOS reset yet as I previously had to change a setting to get Virtualbox to run and I can't remember what the setting was!