Not swithching on, if connect to power flashes a green light,motherboard light flashes also on green,fans off,harddrive not spinning.whats the problem

Okay.

Provided you have checked out the simple stuff; monitor, AND monitor cable, suggestion would be to install a graphics card, and connect the monitor to it.

You won't have THE drivers for the graphics card installed yet, as you have no display, but you should get a display you can see well enough, to install the drivers.

I do need to ask a few questions before this is done, however.

1) Do you know the Power Supply is good?
Your LED lights may light, fans may spin, and it may sound like the harddrive is spinning, but the Processor may not be on.

Why?

A) IF, all of the LED lights were on at once, they would use less than 1 Watt of power.

B) EACH fan uses 2 to 3 Watts of power.

C) A typical Processor can use 51 to 125 Watts of power. Just depends on what Processor it is.

{ The Intel D945GCNL mobo has an LGA 775 processor socket.
Front Side Bus support is 800MegaHertz.

The motherboard chipset is an Intel 945GC (Part number 82945GC)
Can use up to an Intel Core2 Duo processor, with a 800MHz FSB.
These processors can use up to 65 Watts.

http://en.wikipedia.org/wiki/List_of_Intel_chipsets#Core_2_chipsets

I'll go with the chipset info, and not the stated 1066MHz support,

http://www.overstock.com/Electronics/Intel-Essential-D945GCNL-Desktop-Motherboard-Intel-945GC-Express-Ch-Refurbished/6113423/product.html

Stated facts from Intel,

http://www.intel.com/support/motherboards/desktop/d945gcnl/sb/CS-026727.htm }

2) How do you know the;
A) Processor
B) Harddrive
C) Ram Memory
D) Power Supply
,is fine?

Connected them/it to another working motherboard? Won't work with the harddrive, unless Windows Activation screen comes up, and then the harddrive will be for THAT motherboard, and not the original one.

Post back in a Comment.

Regards,
joecoolvette

remove the laptop battery and power on the laptop and check

See if you plugged in the 4 pin power connector on the motherboard besides the main power connection on the power supply (usually black colored and its a plastic 4 pin connector)

Try another power supply if all else fails. If new power supply does not work with this unit then its a motherboard which is blown and motherboard needs replacing.

Hope this helps

if its a flashing amber check power connection.

most likely the powersupply, i would replace that first. but if you get the same result you will need a new system board.

Green light indicates the monitor is getting power. Nothing coming up on the screen indicates, No Signal.

No signal from the computer. This means the computer itself isn't working.

A bad power supply in the computer can cause this. A bad power supply is the leading cause of desktop computer failure. It is replaceable, and can be done by the owner relatively easy.

You may have a computer tower that the Power light comes on, you hear fan/s spinning, (Including the Power Supply fan), and it sounds like the harddrive is running.

ALL the lights in your computer use less than 1 Watt.
EACH fan uses 2 to 3 Watts.
A harddrive sitting there spinning in an endless loop, consumes about 2 to 3 Watts.

A Processor uses 51 to 125 Watts. Depends on what Processor it is.

A weak Power Supply will have enough power for lights, fans, and that harddrive sitting there spinning.
It won't have enough power to turn on the Processor.

[No processor operating, then the harddrive sits there spinning in an endless loop, because there is no processor to find the boot sector]

For a test, connect your monitor to a know good computer. See if it works.
Now connect that other monitor to your computer.

1.Check the Electrolytic Capacitors on the motherboard. Specifically the one's around the processor. These are Voltage Regulators for the processor.
The processor must have DC voltage within a specific range. This zone, or range is very small. Too much voltage, the processor turns off, or won't start up. Too little voltage does the same.

This link will show what Electrolytic Capacitors look like, and what they look like when they are failing, or have failed,

Electrolytic Capacitors are the number one weakest link, of computer hardware failure.
For ease of explanation of construction of them, they look like little aluminum pop cans, they have a rubber seal at the bottom of them, and inside them they have Electrolytic paste.

When the capacitors start to fail, the paste inside develops a gas.
(Hydrogen gas) This gas expands, and pushes the against the seal. The seal's edge pushes out of the 'can', and paste starts to ooze out. So much paste loss, and the capacitor operates at a weakened state. Too much paste loss, and the capacitor fails.

Besides the motherboard capacitors failing, the next area to watch are the one's in the power supply. Power supply's have voltage rails inside. More specifically, they have a 3.3 volt rail, a 5 volt rail, and a 12 volt rail. Voltage may be thought of as the 'speed' of electricity. Amperage may be thought of as how much.
Volts times Amps = Watts.

If you have a power supply with weak, or failed capacitors, you won't be getting the full wattage your computer needs. Your motherboard power light will light up, other lights will light up, fans will spin, and the harddrive sounds like it's working.

ALL the lights use less than 1 Watt.
EACH fan uses 2 to 3 Watts.
The harddrive just sitting there spinning it's platters, uses about 3 to 5 Watts.
PROCESSORS use 55 to 125 Watts!!

So you see you can have lights lit, fans spinning, and the harddrive spinning, but when BIOS tries to turn the processor on, it can't!
Not Enough POWER!

Looks like the lights are on? Fans spin? Sounds like the harddrives spinning? The power supply is bad. has just enough power to light lights, and spin fans, but not enough for the processor. (No beep sounds, because BIOS hasn't done a memory count. It's not going to)

ALL the lights use less than 1 Watt.
EACH fan uses 2 to 3 Watts.
The harddrive just sitting there spinning, uses about 5 watts.

Processors use 55 Watts to 125 Watts. Depends on the processor.
Not enough power to turn the processor on, the computer won't work. Computer isn't working there isn't anything to turn the monitor on. No Signal.

The 'cure' for this is to replace the power supply.
Inside your power supply are Electrolytic Capacitors. These are Filters for a power supply. To simplify detailing the construction of them, let's just say they are small aluminum 'cans', with an Electrolytic paste inside.

They are used to filter the incoming AC electricity from your house, (Business, school, whatever) They are also used to filter the DC electricity, coming out of the power supply. (Your computer power supply converts AC electricity, into DC electricity)

The one's we're going to concern ourselves with here, are the Output capacitors. The one's that filter raw DC into true DC.

When a capacitor (Of this type) starts failing, it's because Electrolytic paste is developing a gas inside. (Hydrogen gas) The gas expands, breaks a seal, and begins pushing the paste out. (Oozing out)
So much paste loss, and the capacitor can still function, but at a weakened state.

These capacitors deal with the voltage power rail for a power supply. Weak capacitor? Weak voltage rail!

Your processor requires a steady, 'clean', supply of DC voltage. It operates in a very TIGHT tolerance. Too much, or too little, it turns off. Too little it doesn't turn on.

The power surge has weakened Electrolytic Capacitors inside your power supply.
Lights light up. Fans spin. It sounds like the harddrive is running. (It IS! It's just sitting there spinning. More about that to come)

ALL the lights use less than 1 watt. EACH fan uses 2 to 3 Watts. The harddrive just sitting there spinning, uses about 5 Watts.

When it's time for the processor to turn on, (BIOS turns it on), it can't! Processors use 55 Watts to 125 Watts. Depends on the processor make and model.

Your harddrive just is just sitting there spinning, because the processor isn't running.

Solution? Replace the power supply, be happy.

Either the new power supply you purchased is not functioning correctly. But, assuming it is now that you are getting some form of power to your PC, it is very likely the motherboard. Whatever fried your old power supply (or it could have just been the power supply itself) most likely fried your motherboard in the process. Probably not the CPU since the MB can't even post.