My PC, an acer veriton m460, 1.5Gb ddr2 ram, celeron a @220 2GHz 160Gb sata2 hddr, nvidia 9400gt 512mb ddr2. Atapi dvd rom. Are the specs.
The problem is that whenever I switch it on, it doesn't boot up. First time it just makes a post beep sound but doesn't proceed from there,monitor just says no signal and light goes orange. Everythng will be on,the hddr, dvd rom and all fans.
When I switch it on again it comes on for a second then off for about 3 seconds then it comes on but doesn't make any beep sound. I then switch it off again and on this time the PSU fan may make a lot of noise, still won't boot.
After a number of attempts of switching on and off it eventually boots.
We have lots of power cuts it our country, about 2 times a day, in the morning and in the evening.
Can anyone help me solve this problem. I hope my mobo is not dying on me.
I have tried dusting the CPU. I have removed my graphics card. I removed the external usb devices like the mouse and keyboard. I even reset the motherboard by removing the cmos battery. The problem is still persistent.

Have You tried to re install your operating system? There is also a chance that Your mother board is not functioning right- it may be caused by the power cuts. A critical software error if You are using windows is usually not a rare thing either , after an unexpected power down.

I have reinstalled my OS. Am using Windows 7 and it never gives me problems once it has successfully booted. However I have noticed that when I'm trying to turn it on , the computer makes a funny 'wheezing' noise before it just goes off. All this happens before it gets to start windows.
We do have several unexpected powercuts. Is there any way other than getting a new MOBO that I can fix this problem.

Finally solved the problem. The mobo had 3 faulty capacitors that I had to replace. Now it working like its new...