Computer turns on but monitor is blank no power to keyboard

[Lizcarter]

Hi, everything has been running fine, I run a diagnostic check on the system every week and everything has been coming back good. My computer appeared to be stuck in sleep mode, the power button was orange, the keyboard had power because the caps lock light would turn on. I couldn’t get it to respond so I shut down manually. When I restarted you can hear the fans come on, but not the normal booting up noises, the power light stays off, and no lights on my keyboard will light up, also monitor stays dark. I tried the hard reset where you unplug completely and hold down the power button for 30 sec. I thought it might possibly be my power supply so I switched it out. Still makes same sound when turning on, just fans, still no light on power button, no lights on keyboard, and dark monitor. I’ve tried different USB ports for the keyboard, and have plugged in a different keyboard with same results. Please help! 

[BeemerBiker]

This is not good.  It appears you have done all the right things.

My recommendation is to open it up and clean it through with an Air Duster.

The following might be helpful for disassembly

https://www.youtube.com/watch?v=r8HsaotN0Cs

After cleaning then remove the ram memory sticks and re-seat them. Look for any obvious problems such as stains on the motherboard where something leaked.  Compare the electrolytic capacitors to images  of defective ones.  If you spot problems take a picture.  If worth repairing you can show the pictures to the local service or "fixit" person so they can give a better estimate.  Frequently the cost of repair is more than the cost of a used system on eBay.

DId you hear any beeping noises/  When you power it on do the keyboard LEDs flash briefly then go out?

Regards