IBM 7133 Series Service Manual

Disk Drive Module LightsThe disk drive module lights at the front of a 7133 are always visible. The disk drive| module lights at the back of Models 010 and 020 are not visible when the back door of the| rack is closed; those at the back of a Models 500 and 600 are not visible when the back| cover of the 7133 is closed.1 Power light ( ): This green light is on when dc voltage is present and inside thespecified limits.2 Ready light ( ): This green light shows the following conditions:Status of Light MeaningOff Both SSA links are inactive because one of the following conditionsexists: The disk drive modules, dummy disk drive modules, or module andSSA adapter that are logically on each side of, and next to, thismodule are not connected or are missing. The disk drive modules or module and SSA adapter that arelogically on each side of, and next to, this module are inactive. An SSA adapter that is in the loop is inactive. A power-on self-test (POST) is running on this disk drive module.Permanently on Both SSA links are active, and the disk drive module is ready to acceptcommands from the using system. The Ready light does not show thatthe motor of the disk drive module is spinning. The module might bewaiting for a Motor Start command, or might have received a MotorStop Command.Slow flash(two seconds on,two seconds off)Only one SSA link is active.Fast flash(five times persecond)The disk drive module is active with a command in progress.1-8 7133 Service Guide