Dell 755 manual Diagnostic Lights, 347, Light Pattern Problem Description

Diagnostic Lights

CAUTION: Before you begin any of the procedures in this section, follow the safety instructions in the Product

Information Guide.

To help troubleshoot a problem, your computer has four lights labeled 1, 2, 3, and 4 on the front panel. When the computer starts normally, the lights flash before turning off. If the computer malfunctions, the sequence of the lights help to identify the problem.

NOTE: After the computer completes POST, all four lights turn off before booting to the operating system.

Light Pattern Problem Description Suggested Resolution

The computer is in a normal off condition or a possible pre-BIOS failure has occurred.

The diagnostic lights are not lit after the computer successfully boots to the operating system.

•Plug the computer into a working electrical outlet (see "Power Problems" on page 339).

•If the problem persists, contact Dell (see "Contacting Dell" on page 370).

A possible processor failure has occurred.	• Reseat the processor (see Processor
	information for your computer).
	• If the problem persists, contact Dell (see
	"Contacting Dell" on page 370).
Memory modules are detected, but a memory	• If two or more memory modules are
failure has occurred.	installed, remove the modules (see
	"Removing Memory" on page 316), then
	reinstall one module (see "Installing
	Memory" on page 314) 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" on page 314).
	• If the problem persists, contact Dell (see
	"Contacting Dell" on page 370).
A possible graphics card failure has occurred.	• Reseat any installed graphics cards (see the
	"Cards" section for your computer).
	• If available, install a working graphics card
	into your computer.
	• If the problem persists, contact Dell (see
	"Contacting Dell" on page 370).

Solving Problems

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