Question Computer turns on but no display and USB ports not powering up

[Curesto]

Hi. I have this following system:
CPU: Intel Xeon X5450 3.00GHz
Motherboard: ASUS ROG Commando
Memory: Kingston 2x2GB 2x1GB DDR2 800MHz
GPU: Sapphire R9 280X Tri-X OC 3GB GDDR5 384-BIT
HDD: Samsung HD250HJ 250GB 7200RPM
PSU: Gigabyte P650B 650W 80+ Bronze

It was working fine but now it not showing up any display. I have tested PSU, GPU and HDD on different system they working fine. I have removed CMOS battery but still no display.

Fans are spinning, CPU, GPU, memory and chipset are heating up so they getting power but no display. Also USB ports are not powering up.

Maybe motherboard is malfunctioning but i don't know for sure.

How to troubleshoot this computer?

Thanks.

 

[Fix_that_Glitch]

Try removing all memory sticks while pc is off and place one in at a time then turn pc on, (in first slot) if no display remove and place next one in, repeat.

 

[geofelt]

Mismatched ram is always a suspect.

Run memtest86 or memtest86+
They boot from a usb stick and do not use windows.
You can download them here:

MemTest86 - Official Site of the x86 Memory Testing Tool

MemTest86 is the original self booting memory testing software for x86 and ARM computers. Supporting both BIOS and UEFI, with options to boot from USB.

www.memtest86.com

Memtest86+ | The Open-Source Memory Testing Tool

Memtest86+ is an advanced, free, open-source, stand-alone memory tester for 32- and 64-bit computers (UEFI & BIOS supported)

www.memtest.org

If you can run a full pass with NO errors, your ram should be ok.

If ram is ok, the next suspect is the motherboard.

Probably best to consider a cpu/mobo/ram upgrade.
$250 could buy a vastly more capable processor, motherboard and 16gb of ram.

 

[DSzymborski]

Did you test another PSU in this system rather than other way around? I'd like to rule out the PSU conclusively in a way better than you chose; your system may be more stressful to a PSU. As a rule, it's best to test other PSUs in the problem system, not a potentially problematic PSU that was already mediocre to start with in another working system