Computer not starting but Mouse LED, Keyboard LED, Monitor, LAN Card LED even Mother Board green LED is on

[goddess_pritha]

I have facing this mysterious problem from last 3 months. Its a very rare problem I m facing this 4 or 5 times in last two month. last evening when a loadsheding occur I just shut down the PC and and after half or 1 hour when the power return, I try to start up my pc but it won't start.
When I press the POWER button, HDD red LED light and blue color power LED light had not blinking but surprisingly mouse and keyboard are in working mode as their LED lights are on and DVD drive LED was also blinking. Then I open the cabinet and see fans are still running (PSU Fan also), don't hear any mysterious beep sound even the green LED of mother board and LAN card are also blinking but along with them a bright red LED of motherboard is also ON (not blinking, its still) which I never see before, when the PC work properly.
I had nothing to do in this prob I just unplug all the cables and plug-in again, remove the RAM clean it with soft paper and attach it again but nothing happen! I try almost the whole night but PC won't start again. but today morning when I again press the power button with a last hope, surprisingly its start up and now its working fine! I have faced this problem before several times. I had another problem, some times my pc suddenly shutting down when I m working (not properly shut down, its like a power failure if I don't have any UPS). Some times my mouse got hanged for for few seconds when a voltage fluctuation is occur on UPS. Don't know whether this all problems are connected with each other or not. If anyone have any idea then pls help me. Its just a 6 month old PC.
PC SPECIFICATION

 

[hans_pcguy]

I would check voltages. If you can, check the voltage at the wall, making sure it is in spec. Check the voltages of the power supply also. You could be having a low voltage on the 12 Volt rail.

 

[goddess_pritha]

First of all thank u so much for thinking about my problem.
Few mins ago I gve a phone call to a mechanic and told him everything about the problem. He also say that its the issue of voltage and he suggest me to bring my CPU to his shop that he could check it.
Yes, u r right. voltage is a big issue in my locality that sometime my Split AC also gt sudden Power Off during Voltage Fluctuation. So few days ago I bought a 3Amp Voltage Stabilizer for our home and connect it with the inverter machine which now control my UPS as well as other electrical goods like fans and lights (Not the AC. It has another stabilizer which connected directly to the meter box, not with inverter). But I still facing the same problem
One more thing, How can I check the voltage of my Power Supply? the LED display of my digital voltage stabilizer shows a 3 digit number which varries in between 180 to 230. is it deal anything with voltage? Few mins ago I again face that same prob. PC gt sudden power off during this post. ohh god! itz made me crazy
Ok. Here is another specification about the CPU voltage. Hope it will be helpful.