HP EML E-series Tape Libraries - Manual (Page 59)

Figure 39 Indicator on an LTO2 or LTO3 tape drive
Table 13 Indicator on an LTO2 or LTO3 tape drive
Index
No.
Control/indicator Function
1 FAULT LED
When lit (yellow), indicates that initialization is in
progress, the library robotics controller software has
detected a failure that requires the replacement of the
tape drive assembly, or a hot swap can occur.
When not lit, indicates normal operation.
Enterprise Modular Library E-Series 59