Cisco Systems CISCO1750 manual OK LED Diagnostics, Number of Blinks, Meaning

Problem Solving

•ISDN configuration—Consider ISDN-specific hardware and software configurations (ISDN BRI WICs only).

OK LED Diagnostics

Use the front-panel OK LED to help determine any problems with the router. When the router first boots up, it performs a power-on self-test (POST). If the router detects a problem during the POST, the OK LED blinks in a different pattern (described in Table 1), depending on the problem. A pattern is a specific number of blinks that is repeated until the router is turned off. If the router experiences any of these problems, contact your Cisco reseller.

Table 1	OK LED Blinking Patterns
Number of Blinks		Meaning
2		The 860T dual-port RAM (DPRAM) failed.
3		The parameter RAM area of the 860T DPRAM failed.
4		The 860T system protection control register has a write
		failure.
5		The router cannot detect the dynamic RAM (DRAM).
6		The user programmable machine has a write failure.
9		The router DRAM failed.

Cisco 1750 Router Hardware Installation Guide

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