Pc has no display but fans are running loud

[JohnVega]

Hello, I'm new in this community. Please bear with me. 

I have HP Compaq dc5800 Small Form Factor. Yesterday, when I turned on my computer it has no display and after a few seconds the fans begin to run loudly. It can't be turn off when I'm pressing the power button even for a long time, so I turned it off in AVR. I turned it on again, then boots properly. The problem is that when I turned on my computer today, it goes the same way like what happened yesterday and now I can't fix it. I cleaned it all earlier including its case and internal components. I removed all the RAM but my computer doesn't beep and the power still turns on with no display. What do you think is the problem?

[old_geekster · Accepted solution]

@JohnVega , welcome to the forum.

My first thought is that the power supply unit (PSU) has failed because of the age of the computer (2009).  The PSU will cause many problems that don't appear to be power related, such as, freezing.  There will normally be some signs of failure prior to it failing, but it can fail abruptly.  There are numerous guides/videos online to help you test the PSU.

If you want to test the memory, you can install one stick at a time in socket # 1 (closest to the processor) and boot.  Do this with each stick to see if it boots.

Please click the Thumbs up + button if I have helped you and click Accept as Solution if your problem is solved.

[JohnVega]

I fixed the problem. You were right, it's the PSU that has failed because there's something wrong in its cable/wire. It was bended and slightly cut off so I just shredded its wire and connect it.

Anyway, thanks for your help. I will accept it as a solution. By the way, the RAMs are completely fine. 

[old_geekster]

You are welcome, @JohnVega!  I am glad to help you solve the problem.  It is good that the RAM has not failed.