Cisco Headend Digital Broadband Delivery System Manual De Mantenimiento
Appendix A
Bootloader LED Error Codes
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4024836 Rev D
Bootloader Error Codes for Three-LED DHCTs
Low-level bootloader error codes on the three-LED DHCT display if there is an error
condition detected by the bootloader when the DHCT boots, or when it loads or
installs software.
The DHCT displays the error code for a little over a second and as many as 10 times.
The DHCT displays the error code for a little over a second and as many as 10 times.
Before the DHCT displays the error code, all three LEDs are off.
All off [error code] [error code] [error code] [repeats up to 10 times] All off
Reading Bootloader Error Codes on the Three-LED DHCT
Error codes are displayed by the 3-LED DHCTs as a series of bright and dim
illuminations, which correspond to the ones and zeros of a digital code. The bright
illuminations represent 1 (or 'on') digits, and the dim illuminations represent 0 (or
'off') digits. The LEDs are on the face of the DHCT.
Important: Some DHCTs have 4 LEDs; however, the error codes will also use this 3-
LED illumination pattern.
Each code represents a subset of a binary code. The binary code has an arbitrary zero
Each code represents a subset of a binary code. The binary code has an arbitrary zero
(0) added before the most-significant digit to round the code to 9 bits (3 codes with 3
bits each). Ignore the first zero in the code.
Example:
The LEDs display the following codes:
Example:
The LEDs display the following codes:
Left LED
Middle LED
Right LED
Code
dim
dim
dim
000
bright
dim
bright
101
dim
dim
bright
001
This LED pattern represents a code of 000 101 001. Removing the leading 0 results in
the binary code of 0010 1001, a hexadecimal value of 0x29.