Hi netter909,
Dell Dimension 2400 has Diagnostic Indicators on the system.
The first diagnostic feature uses the diagnostic LED quad pack on the rear of the system to relay information about the health of the hardware. The 4 LEDs illuminates in two different colors. This allows for different patterns to give users clues as to what system is doing.
The second diagnostic feature uses beep codes and text error messages to relay information about a previous boot failure. If the BIOS sees that the previous attempt at booting was unsuccessful, it will notify the user. This information will be displayed on the screen with a TBD message similar to the following…
Error! The previous boot failed to complete.
Last reported checkpoint was [Emem]
If the previous boot failed before video was initialized, it is highly likely that this boot will also fail before video. In this case, the BIOS uses beep codes to relay the offending checkpoint to the user.
Please let me know the findings.