Service Reference Guide, dc5000
360201-002
3–5
Desktop Management
3.4.3 FailSafe Boot Block ROM
The FailSafe Boot Block ROM allows for system recovery in the unlikely event of a ROM flash
failure, for example, if a power failure were to occur during a ROM upgrade. The Boot Block is a
flash-protected section of the ROM that checks for a valid system ROM flash when power to the
system is turned on.
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If the system ROM is valid, the system starts normally.
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If the system ROM fails the validation check, the FailSafe Boot Block ROM provides
enough support to start the system from a ROMPaq diskette, which will program the system
ROM with a valid image.
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Some models also support recovery from a ROMPaq CD. ISO ROMPaq images are included
with selected models in the downloadable ROM softpaqs.
When the bootblock detects an invalid system ROM, the System Power LED blinks RED 8
times, one every second, followed by a 2-second pause. Also 8 simultaneous beeps will be heard.
A Boot Block recovery mode message is displayed on the screen (some models).
To recover the system after it enters Boot Block recovery mode, complete the following steps:
1. If there is a diskette in the diskette drive or a CD in the CD drive, remove the diskette and
CD and turn off the power.
2. Insert a ROMPaq diskette into the diskette drive or, if permitted on this computer, a
ROMPaq CD into the CD drive.
3. Turn on the computer.
If no ROMPaq diskette or ROMPaq CD is found, you will be prompted to insert one and
restart the computer.
If a setup password has been established, the Caps Lock light will turn on and you will be
prompted to enter the password.
4. Enter the setup password.
If the system successfully starts from the diskette and successfully reprograms the ROM,
then the three keyboard lights will turn on. A rising tone series of beeps also signals
successful completion.
5. Remove the diskette or CD and turn the power off.
6. Turn the power on again to restart the computer.
The following table lists the various keyboard light combinations used by the Boot Block ROM
(when a PS/2 keyboard is attached to the computer), and explains the meaning and action
associated with each combination.
