GPU & motherboard both sending 'no video signal' to monitor

[therumpledacademic]

I run an R9 390x GPU on a MSI Z270i motherboard, and while using the PC a few hours ago (not doing anything out of the ordinary, no new drivers or anything), the screen suddenly went black. I restarted the computer, and even though the fans and motherboard lights are active, I'm still just getting a "no video signal" message on my monitor.

I have tried:
- changing from DisplayPort to HDMI on the GPU (no difference)
- testing the monitor by connecting it to my old laptop (the monitor and HDMI connection are both working fine)
- removing the GPU on my PC and trying to connect the monitor directly to the motherboard, both through DisplayPort and through HDMI (no difference. Still just "no video signal". This is about when I started getting properly worried...)
- clearing the CMOS (no result)

Any ideas? The one time something similar to this has happened, it turned out that my GPU had gotten unseated somehow. But that's definitely not the case this time -- I've re-seated it twice now, and the GPU fans are spinning when I turn it on, so it's clearly connected. My keyboard lights up when I turn it on, so power is still going to the peripherals. I've currently got the GPU unseated, but I'm just getting no video signal no matter what I do, and so can't even access the BIOS. Can anyone help?

 

[smorizio]

the r390 card is a high wattage card. you error sounds like one of the legs on the power supply is outputting less then the atx spec. if you dont have a spare power supply try and do a cross ship with the one you have. if your unit is not a good unit (you did not post it). for that gpu the min wattage was 650w. i would look at a good 750w unit.

 

[Jack1369]

I had a similar issue. Turned out it was the motherboard not sending stable power currents. If you have another board, give it a try

 

[therumpledacademic]

the r390 card is a high wattage card. you error sounds like one of the legs on the power supply is outputting less then the atx spec. if you dont have a spare power supply try and do a cross ship with the one you have. if your unit is not a good unit (you did not post it). for that gpu the min wattage was 650w. i would look at a good 750w unit.

Interesting, thanks. My power supply is a 600w one, which is within what the PSU calculators on the internet told me I'd need, even accounting for such a high wattage card. The particular power supply I've got is this one (http://www.corsair.com/en-us/sf-series-sf600-600-watt-80-plus-gold-certified-high-performance-sfx-psu), and it's worked fine for the last year. Maybe it's degraded in that time? I don't have a spare power supply to test unfortunately, but hopefully there's some other way of determining if the power supply is definitely the culprit ...

Could you explain what you mean by "try and do a cross ship with the one you have"? I've tried looking that phrase up, but can't find anything.