Dell 720H2C appendix Beep Codes, Code Cause

A possible graphics card failure	•	Reseat any installed graphics cards (see Cards).
has occurred.	•	If available, install a working graphics card into your computer.
	•	If the problem persists, contact Dell (see Contacting Dell).
A possible floppy drive or hard	Reseat all power and data cables.
drive failure has occurred.
A possible USB failure has	Reinstall all USB devices and check all cable connections.
occurred.
No memory modules are	•	If two or more memory modules are installed, remove the modules (see Removing Memory), then
detected.		reinstall one module (see Installing Memory) and restart the computer. If the computer starts
		normally, continue to install additional memory modules (one at a time) until you have identified a
		faulty module or reinstalled all modules without error.
	•	If available, install working memory of the same type into your computer (see Installing Memory).
	•	If the problem persists, contact Dell (see Contacting Dell).
Memory modules are detected,	•	Ensure that no special requirements for memory module/connector placement exist (see
but a memory configuration or		Memory).
compatibility error has occurred.	•	Ensure that the memory you are using is supported by your computer (see Memory).
	•	If the problem persists, contact Dell (see Contacting Dell).
A possible expansion card failure	1.	Determine if a conflict exists by removing an expansion card (not a graphics card) and restarting
has occurred.		the computer (see Removing PCI and PCI Express Cards).
	2.	If the problem persists, reinstall the card you removed, then remove a different card and restart
		the computer.
	3.	Repeat this process for each expansion card installed. If the computer starts normally,
		troubleshoot the last card removed from the computer for resource conflicts (see Troubleshooting
		Software and Hardware Problems).
	4.	If the problem persists, contact Dell (see Contacting Dell).
Another failure has occurred.	•	Ensure that all hard drive and optical drive cables are properly connected to the system board
		(see System Board Components).
	• If there is an error message on the 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.
	• If the operating system is attempting to boot from a device (such as the floppy drive or optical
		drive), check system setup (see System Setup) to ensure the boot sequence is correct for the
		devices installed on your computer.
	•	If the problem persists, contact Dell (see Contacting Dell).

Beep Codes

Your computer might emit a series of beeps during start-up if the monitor cannot display errors or problems. This series of beeps, called a beep code, identifies a problem. For example, beep code 1-3-1 (one possible beep code) consists of one beep, a burst of three beeps, and then one beep. This beep code tells you that the computer encountered a memory problem.

Reseating the memory modules may correct the following beep code errors. If the problem persists, contact Dell (see Contacting Dell) for instructions on obtaining technical assistance.

Code	Cause
1-3-1 through 2-4-4	Memory not being properly identified or used
4-3-1	Memory failure above address 0FFFFh

If you experience any of the following beep code errors, see Contacting Dell for instructions on obtaining technical assistance.

Code	Cause
1-1-2	Microprocessor register failure
1-1-3	NVRAM read/write failure
1-1-4	ROM BIOS checksum failure
1-2-1	Programmable interval timer failure
1-2-2	DMA initialization failure
1-2-3	DMA page register read/write failure
1-3	Video Memory Test failure
1-3-1 through 2-4-4	Memory not being properly identified or used
3-1-1	Slave DMA register failure
3-1-2	Master DMA register failure
3-1-3	Master interrupt mask register failure
3-1-4	Slave interrupt mask register failure
3-2-2	Interrupt vector loading failure