IBM 3590 - Manual (Page 85)

v “Cell Status: Steady Green–In-Use Indicator LED” on page 66.
Cell Status: Flashing Yellow–Attention indicator LED
The device requires operator assistance. Table 26 describes the Attention
condition. There will be a corresponding operator panel ATTN ACF message
in the case where the LEDs indicate attention.
Table 26. Cell Status Indicator LEDs Flashing Yellow–Attention Indicator LED
Indicator LED State Description of the Condition
All 11 LEDs -- magazine LEDs
and the priority cell LED -- are
flashing yellow (Accumulate,
Automatic, Manual, and
System modes) or all 10
magazine LEDs are flashing
yellow (Random mode). Further activity is stopped. Requires operator
attention such as installing the magazine, locking or
unlocking the magazine, clearing a cartridge jam,
and so on. Once the condition is cleared the LEDs
return to normal after Start is selected. Typical
supplemental messages to ATTN ACF include extra
cartridge, picker error, and export error.
Chapter 4. Automatic Cartridge Facility (ACF) and Magazine 65