Dell Optiplex GX280 won't start, amber light flashing

Hello there, I am facing some issues with my Dell desktop. I have a Dell Optiplex GX280 which is installed with Windows XP operating system. The problem is the system is not booting. Whenever the power button is pressed, the computer wont boot. I cant figure out what is causing such problem and hence need your help in solving the issue. Therefore if anybody knows why my Dell Optiplex GX280 won't start, then please share some information which might help me in solving the issue. Thanks in advance.

Motherboard of the computer is responsible for controlling all the actions which are performed by the computer. It is responsible for providing correct voltage to all the peripherals which are attached to the computer. If the motherboard of the computer is not working properly then the computer wont start. Therefore get the motherboard of the computer checked by some technician and get it replaced if there is any fault in it. After replacing the motherboard, check if the computer is booting or not.

All the files which are required for the operating system to boot are first loaded in the system RAM of the computer. If the system is not able to access the system memory then the files which are required for the system to boot will not be copied to the system RAM and hence the system will not boot. Hence open the computer and remove the RAM chips from their respective slots. Clean the connecting terminals of the RAM and replace them in their respective slots. See if the computer is booting. If there are multiple RAM chips then try booting the system using single RAM chip at a time.

There is a battery situated on the motherboard of the computer which is responsible for saving all the settings which are required for the computer to boot. Open the computer and locate the battery on the motherboard of the computer. Remove the battery and then check the voltage across the battery using digital multimeter. The voltage across the battery should be between 2.5 volts to 3 volts. If the voltage of the battery is less than 2.5 volts then you will have to replace the battery as the computer will not boot with right battery voltage.

By looking at the problem it looks like a faulty power supply issue. All the devices which are connected to the computer, require a correct level of voltage all the time to work properly. If the voltage to the any device is fluctuating then the computer wont boot. The amber light which is flashing indicates that there is some power issue with the computer due to which it is not starting. Get the Power supply unit checked and then see if there is any problem with it or not. Replacing the power supply unit will solve the problem.

I have six of the same units, and couldn't get them to boot, power light flashing, ect.
Took off the heat sink, cleaned the back of the processor and the heat sink, applied new thermal compound, and replaced the heat sink.
Under one side of the bracket that the processor clips in to I slid a piece of 1/32" plastic between the clip and the top side of the heat sink, pushing it down towards the processor.
All six units work great now.
Hope this helps.
Seems like a design flaw.