Please help: Sabertooth 990fx boot device led lit with no post

[Obsidus]

First let me apologize for any poor typing, as I'm doing this on my S4 and am not the best at texting. Anyhow!

A few weeks ago my computer started acting up, and at first it was the VGA led that was staying lit, with nothing displaying on the monitor. I went through the usual procedure of clearing the cmos and making sure all cables/ the ram were seated properly. Eventually I got it to work, and found out I had gotten a Trojan somehow (which I took care of) and figured that was what was causing the issue. A few days later the dimm led was staying lit and it again was not displaying anything, not even the bios. I took out the ram, sprayed it down with circuit board cleaner and replaced it; this lead to the computer again appearing to function properly.*

Now a few days ago it was doing it again, but this time it was the boot device led that was lighting up. So I pulled the cmos and left it overnight. In the morning I put the battery back in and started it up. This time instead of the TUF splash screen and the uefi bios, I got a black bios screen with white text, giving me the option to reset to default settings, which I did. The computer hasn't worked since.

I've tried the jumper, mashing f2 on startup, I took the the comp apart and reassembled it securely, I tried running it with only 1 dimm, without the ssd plugged in, the mem ok button, and I even bought a new cmos battery; nothing works. All the lights turn on, all the fans start up, and the mouse and my Nostromo light up; furthermore all of the motherboards diagnostic leds cycle, but the boot device led stays lit and nothing shows up on the monitor. I'm completely at a loss. I have a thumb drive in the USB port to try flashing the bios, but I cannot even do that.

So I guess my questions are: does anyone have any idea what is going on, how can I fix it, and if it is a lost cause what part do you think I need to replace? Before someone suggests it, no I do not have spare parts to switch them out.

Here is my build:

Asus Sabertooth 990fx
8 GB of G-Skill Rip jaws
AND FX-4170 cpu
MSN Twin Frozr III 7850
Corsair HX 750 psu
Crucial M4 ssd
Windows 7 home edition

Thank you ahead of time.

 

[Obsidus]

Bump.

 

[SilthDraeth]

Call Asus, usually, 3 year warranty on motherboard, but that one may be a 5 year. RMA your motherboard, when new one arrives put it all back together.

 

[Lorne]

See if you can barrow another power supply.

 

[ratjacket]

from your post im not 100% sure what have you tried

does you computer complete the POST is there a beep code

have you tried a bare bones boot (no usb plugged in, no cdrom, just the basics no HDD even(to see if it posts and dispalys on monitor), 1 stick of ram (try each one as well by them selves, keep your gpu but you may want to try using the intergrated if you have it)

also a bare bones boot with a different keyboard, no mouse.

have you tried a new monitor or monitor cables is it booting from intergrated GPU or your dedicated GPU, try both.

is it infact posting but just not displaying anything.

(make sure you discharge all stored energey before you change any components this requires unpluging from wall and powering on while unpluged)

sometimes cold booting vs booting with the caps charged can a make a difference i.e reset instead of power off after it fails to boot or boot after you have discharged all stored current.

 

[Obsidus]

from your post im not 100% sure what have you tried

does you computer complete the POST is there a beep code

have you tried a bare bones boot (no usb plugged in, no cdrom, just the basics no HDD even(to see if it posts and dispalys on monitor), 1 stick of ram (try each one as well by them selves, keep your gpu but you may want to try using the intergrated if you have it)

also a bare bones boot with a different keyboard, no mouse.

have you tried a new monitor or monitor cables is it booting from intergrated GPU or your dedicated GPU, try both.

is it infact posting but just not displaying anything.

(make sure you discharge all stored energey before you change any components this requires unpluging from wall and powering on while unpluged)

sometimes cold booting vs booting with the caps charged can a make a difference i.e reset instead of power off after it fails to boot or boot after you have discharged all stored current.

I have tried without the hdd plugged in, and also with nothing plugged into any of the USB ports. Have also tried one stick of ram. I do not have any integrated graphics I do not believe, and the mobo has no speaker so there are no beeps for a post code.

 

[Ketchup]

This sounds like the board, but have you tried putting your video card into the other pci-express slots?

 

[ratjacket]

Have you tried a new montior cable or a different monitor

it does sound like the mobo but you want to try everything first

also try a new keyboard or mouse

and like above a different PCI-e slot

does you mobo has an interal speaker header plug a speaker in. and see what post code u get