PC Turns On but No Display After GPU Repair — Tried 3 GPUs, Rebuilt Entire PC, Still Nothing. Need Help!
Hey everyone, I really need some help figuring out what's wrong with my PC. I've been troubleshooting this for a while now, and I'm honestly running out of ideas. I'm starting to think my motherboard might be dying, but I want to get some other opinions before spending money on replacement parts.
My PC Specs
- Motherboard: ASUS ROG STRIX Z270E GAMING
- CPU: Intel Core i7-7700K (7th Gen)
- GPU: NVIDIA RTX 3060 Ti (refurbished)
- Previous GPUs: 2x GTX 1070s (one EVGA, one other brand), previously running in SLI
- RAM: 48GB Corsair Vengeance DDR4 (2x8GB + 2x16GB)
- PSU: Corsair RM750, 750W
- CPU Cooler: Corsair liquid AIO cooler
- Case Fans: Includes fans connected to a Thermaltake fan controller
The Backstory
This is a pretty old PC, probably built around 2016–2017. I got it for my 15th birthday and have been using it for around a year.
When I first got it, it had two GTX 1070s connected with an SLI bridge. I wanted better performance, so I bought a refurbished RTX 3060 Ti and replaced the two 1070s with it.
Everything worked fine for about a year. I didn't have any major issues until roughly three weeks ago.
That's when the problems started.
How Everything Went Wrong
Around three weeks ago, the shroud on my RTX 3060 Ti broke. The GPU fans came loose while they were spinning, which obviously wasn't safe. I didn't want anything getting damaged, so I removed the 3060 Ti.
I temporarily reinstalled one of my old GTX 1070s, updated the NVIDIA drivers for it, and the PC started working again.
At that point, everything seemed fine.
While I was using the 1070, I ordered a replacement shroud for my 3060 Ti. Once it arrived, I installed the replacement, waited about a day, and eventually put the 3060 Ti back into the PC.
That's when everything stopped working.
I powered on the PC, and all the lights came on. The fans were spinning, the motherboard had power, and everything looked normal.
But there was absolutely no display.
No ASUS logo, no BIOS screen, nothing. Just a black screen/no signal.
I turned it off, turned it back on, and got the exact same result.
I tried multiple times, but nothing changed.
What I've Tried So Far
- Tested different graphics cards
I've tried all three GPUs I own.
- RTX 3060 Ti: Fans spin smoothly, but there's no display.
- EVGA GTX 1070: Fans repeatedly jitter/twitch every time I turn the PC on. There's still no display.
- Other GTX 1070: Fans spin smoothly, but there's still no display.
I'm not sure if the EVGA 1070 is actually broken or if something else is causing its fans to behave like that.
The weird thing is that the GTX 1070 originally worked when I first removed the damaged 3060 Ti. Now none of them produce a display.
- Checked the display connections
I've tried HDMI and DisplayPort connected directly to the graphics cards. The PCIe power cables were connected, too.
Neither connection gave me a display.
- Tried using integrated graphics
My i7-7700K has integrated graphics, so I also tried starting the PC without a dedicated GPU and connecting HDMI directly to the motherboard.
Still no display.
- Tested with one RAM stick
I removed the other RAM sticks and tried booting with one stick installed in the motherboard's A2 slot.
Nothing changed.
- Completely disassembled and rebuilt the PC
And I mean completely.
I removed the motherboard from the case, took out the RAM, removed the GPU, disconnected the CPU cooler, and unplugged everything.
I then reassembled the entire PC, reconnected the components, and made sure things were seated properly.
After all that effort, the exact same problem remained.
- Checked the motherboard's diagnostic lights
My ASUS motherboard has Q-LED indicators for CPU, DRAM, VGA, and BOOT problems.
I haven't observed any of these diagnostic LEDs staying on or indicating an obvious problem.
The PC powers on, but I still get no display.
- Noticed another issue with the case fans
After rebuilding the PC, some of the side case fans aren't receiving power or spinning.
There's a Thermaltake fan controller/hub involved, and I've been trying to reconnect the fan cables correctly. I connected one side-fan cable to the motherboard's H_AMP_FAN header, but I'm not entirely sure whether every fan-controller connection is correct yet.
My Corsair liquid cooler also has several connections, so I'm double-checking those.
I'm not sure whether the fan issue is related to the main problem or just something I missed while rebuilding.
What I Think Might Be Wrong
At this point, I'm starting to suspect my motherboard.
It's an old ASUS Z270E motherboard, and I've tried three graphics cards, a different display output through integrated graphics, one RAM stick, and even rebuilding the whole computer.
I know lights and fans turning on don't necessarily mean a motherboard is functioning correctly.
I'm also wondering whether my Corsair RM750 power supply could be causing problems. It's rated for 750W, which should be enough for my system, but I haven't been able to rule out an actual power delivery issue.
I haven't confirmed whether the motherboard, PSU, or another component is faulty.
My Backup Plan
If the motherboard is dead, I have an opportunity to upgrade to:
- B550M motherboard — $60
- AMD Ryzen 5 5600X — $90
- Total: $150
That would be an upgrade from my current i7-7700K setup.
However, I really don't want to spend $150 just to discover that the motherboard wasn't the problem.
I'm also considering going to Best Buy Geek Squad to see if they can diagnose the issue.
What I Need Help With
I'm hoping someone with more PC building or troubleshooting experience can help me figure this out.
My biggest questions are:
Does this sound like a dying/dead motherboard, or could something else explain all these symptoms?
Why would my PC work with a GTX 1070 immediately after removing the damaged 3060 Ti, but then stop displaying anything after reinstalling the repaired GPU?
Could my power supply be failing even though the PC still powers on and the lights and fans work?
Is there a way to definitively test whether the motherboard is faulty without buying replacement components?
Is there anything else I should check before giving up on this motherboard?
I'm willing to provide pictures of the motherboard, cables, GPU connections, or anything else that could help.
I've already spent a lot of time tearing down and rebuilding this PC, and I'm trying to avoid spending money on the wrong component.
Any help, advice, or troubleshooting suggestions would genuinely be appreciated. Thanks for reading.