My computer turns on but nothing is displayed on the screen and also it refuses to turn off by power switch (after holding it down for 10 seconds of course) so I have to shut off the power supply to turn the computer off.

Update: Good news everyone, I replaced the motherboard and it boots. Thank you for the help.

Again, thank you for all the help to everyone who responded. Really appreciate it.

Azza Case
AMD 880k CPU
Gigabyte GT1030 GPU
Corsair CX500M PSU
Samsung Evo SSD 500gb
Gigabyte GAF2A88XN Motherboard

I've tried the following to attempt to solve this (in no particular order):

-Did a search on the net and followed "solutions"

-Replacing the case

-Replacing the memory

-Replacing the power supply (this also meant using new cables than previously used for all other components)

-Resetting the cmos

-Reseating the processor

-Replacing the processor

-Replacing the cpu cooler

-Replacing the graphics card

-Trying the graphics card with another motherboard

-Trying a different pci riser card

-Trying a different hdmi cable

-Tried a T.V. and a computer monitor

-Starting all the components out of the case

-Starting the computer with the case fan

-Checking to see whether all the components are all seated correctly

None of this made a difference but it does seem all the components work fine. The motherboard and power supply were working correctly with a 1080 gtx gpu. I'm really confused. Any help would be appreciated.

There are number of reasons I posted here instead of other forums so any help would be appreciated. Thank you in advance.

Usually the PC speaker [1] will beep for diagnosis purpose.
Check if your PC speaker is plugged in the correct place.

[1] https://en.wikipedia.org/wiki/PC_speaker

First thing i'd check is what kind of output you're giving to your monitor/TV. If it's a TV say using HDMI, if it can't handle certain resolutions it will remain blank.

Computer beeping will be useful if you have a PC speaker, but a number of systems don't include one by default.

If it's a BIOS configuration that's gone wrong, there will be a set of pins for a reset, you put a jumper on for 20 seconds and then take it off, it will reset the BIOS settings, which you can then hopefully do a boot up with.

If all your memory is bad, that will prevent it from working.

If the computer is too cold, it might not work as well, i've had this. If that's the case, turn the computer on, leave it alone like 10 minutes, then turn it off and then back on, it would have warmed up in those 10 minutes enough to work correctly.

I get no visual output from the bios, in case that's what you're asking. The graphics card did work in another machine and the motherboard did as well. The motherboard or cpu has no onboard graphics and that's why I need the card. I will try the system speakers so I could get beeps.

The motherboard and power supply were previously working fine with my gaming rig. It's HDMI and I've tried a computer monitor and an HDTV.

For reset. I disconnected the CMOS battery for 3 minutes and put it back in. Since the jumpers were small, it took an additional 3 minutes to get the battery connected again so it should have reset and as stated before, it made no difference.

I tried a different set of RAM, again no difference.

I will try the system speakers to get the codes and I will try to leave the computer on for 10 minutes.

Thank you for the help, guys.

Hmm.

This is a bit of a stretch, but with so many troubleshooting steps having gone though to not even a visual BIOS...makes me wonder if a trace on the mainboard has been cracked or broken.

Are you shure the monitor cable is plugged into the video card and not into the motherboard?

Did you CLEAN IT OUT sometimes My Pc wouldn't load up unless I CLEANED IT OUT made sure there was no dirt dust and other junk in there!

That would be bad. Last time I tried to transfer the cpu, I ended up breaking it and had to replace it. Well, at least now I know it has nothing to do with the CPU. The motherboard is fairly new though and it was bought brand new. Still, I will check it out. Yes, I'm absolutely sure. I've been checking the hdmi cable every time I plug it in. Yes, I did clean it out. However, the case is new and it is a new build, which is why this is so confusing. The old parts have also been cleaned.

I am about to try to plug in the system speakers to get the beeps.

What operating system? If Windows 7, something similar happened to me, turned out to be a KSOD (unfixable in that case) and I ended up having to get a whole new computer.

Looks like you haven't checked the HDD. Maybe it had a head crash?

Can ssds get that? Also, I'm trying to get a visual, so the ssd is now disconnected. This worked with another computer (without hard/solid drive), so that's why I've gone that route.

Yes, it is Windows 7. I will look into KSOD as well.

Ok, didn't catch that you had an SSD. I thought you had a mechanical HDD. Sorry about that.

No, I don't think an SSD can have a head crash being as it is not mechanical, but I have read that they slowly burn out over time, losing storage capacity and slowing down retrieval rate.

Definitely look into the KSOD thing. It took me down a long convoluted path like you've been down. Hey, it was a good excuse to get a new system, though.

Sounds like you replaced everything except the motherboard.

btw. stop the hdd/ssd advice advice. A system doesn't need a storage medium to POST (or show something on the screen).

Try replacing the battery of the motherboard.

The battery saves the (custom) BIOS settings. Why would a system with a default BIOS not show anything on the screen? It's not like there's an option between onboard and external graphics, in this case.