Why am I unable to boot my desktop dell

An Amber blinking power button indicates a low voltage problem. This can be caused by a defective power supply or a defective motherboard.
Remove any PCI cards like modem, video card, sound card, etc... Remove the memory modules and disconnect cables to CD/DVD drives. Look at the USB ports to see if any are damaged.

An amber light means your computer isn't reading the hard drive or CD right, Take it to a professional to get this corrected

sounds like hard drive dead or your boot files corrupted and your hard drive has no input power. could be power unit weak or your hard drive could have died..they do wear out.
do you hear any fans spinning? there are fans to keep your pc cool. one big one for chasis and one small on over processor chip(heatsink). if the smaller fan(especially) does not spin then PC will not boot because chip will heat up and break if no fan. system will protect itself from this by not starting. open chasis and check if small fan is working. if not this is cheap fix. if it spins then hard drive or graphics card may be bad, which gets more expensive. shop will charge average of $75 dollars to analyze-just to tell you what is wrong, not to fix it.

I think your problem is your memory or video card.

Below are some steps that I recommend.

When you plug in the power cord is there any lights whatsoever on the computer?

When you press the power button do you hear fans running, hard drive spinning, lights on the computer, hear any beeps or lights constantly blinking, hear the DvD/CD drive click and the light on the drawer of the DvD/CD turn on for a second or two? If so the laptop is trying to boot or may have booted, but the screen is not showing for some reason.

Beep tones and blinking lights tells the technicians what is going on with the computer and why it is not booting. Most times it's a motherboard issue when you hear beeps or blinking lights continuous. Most times the problem is with the memory or Video Card. Count the Blinking Lights or Beeps and take note of their pattern (1 Long or 1 Long followed by 2 Short).

Maybe your power cord is bad if you don't get anything to happen whatsoever when you press the power button.

Maybe you have a Static Charge Buildup. Remove the Power Cord, then Press and Hold the power button for 30 seconds. After 30 seconds plug the power cord back in and hit the power button to see if it boots.

Maybe your memory is bad or the memory slot is bad.

Remove the Power Cord, Open the Case and remove one of the memory chips. Set the chip aside then try rebooting the computer. If it boots, then you know the memory chip you set aside is bad so mark an x on it with an ink pen. If it fails to boot then move the chip to the next memory slot and try rebooting. If it fails take the chip out and set it aside, then put the other chip in and try booting it in both slots. If it boots, just to verify that the chip set aside is bad, mark an x on it and put it into the open memory chip slot and try booting.

Maybe your power supply is bad. Sometimes there is enough power to make the power light or some other lights come on but not enough power to make the fan turn on or hard drive spin.

Below are links and info I found from Dell's Website based on your model.


http://support.dell.com/support/edocs/systems/dime521/en/SM_EN/specs.htm

Controls and Lights Front of computer:

Power button - push button

Power light
green light - Blinking green in sleep state; solid green for power-on state.
amber light - Blinking amber indicates a problem with the power supply inside the computer. If the system cannot boot and there is a solid amber light, this indicates a problem with the system board (see "Power Problems" in your Owner's Manual).

Diagnostic lights
four lights on the front panel (see Diagnostic Lights.)

Standby power light
AUX_PWR_LED on the system board

Hard-drive activity light
green light - When the computer is reading data from or writing data to the hard drive.

LAN indicator light

green light - Solid green indicates that a LAN (local area network) connection is established.

http://support.dell.com/support/edocs/systems/dime521/en/SM_EN/adtshoot.htm#wp1056411

Unfortunately the dell website (not me) is not very helpful. Here's what is says about your diagnostic lights


Another failure has occurred.

• Ensure that the cables are properly connected to the system board from the hard drive, CD drive, and DVD drive.
• If there is an error message on your screen identifying a problem with a device (such as the floppy drive or hard drive), check the device to make sure it is functioning properly.
• The operating system is attempting to boot from a device (such as the floppy drive or hard drive); check system setup (see "Boot Sequence") to make sure the boot sequence is correct for the devices installed on your computer.
• If the problem persists, contact Dell.

When you mean the amber light, is that the blinking hard drive access light or the power light? Different cases have different colors on it. Mine has blue and green lights.

If you see the boot screen (bios) and then after it goes to boot, does it blink and hang?

This could be a simple operating system issue, hard drive or hardware/motherboard issue. If you could provide more information, that would help.

Disconnect the hard drive and the floppy drive cable at the mother board. The retry POST and try to clear up any problems in POST. If this works fine then the floppy drive cable is either reversed at the unit or the hard drive is jumpered wrong.

Hi. the mother board seems to be having some initialization issues during boot up. this is common when the mother board is failing. i would check to make sure the battery on this board is working. if it is, the board my be ruined.
power board seems to be fine.
please rate and god bless.

Check motherboard for bad capacitors. I had the same problem and when i had bad capacitors replaced everything is ok.

Hello,
take the PSU (Power Supply Unit) from a known working computer, preferable to be the same model and test with it. when you do so make sure you disconnect any peripherals e.g ( Printer, CD-ROM, Floppy).

Look closely at the memory bay for any bent pins, and test with one memory at the time.

Let me know if this is still an issue.

Regards