3 Check light ( ): This amber light shows the following conditions:Status of Light MeaningOff Normal operating condition.Permanently on One of the following conditions exists: An unrecoverable error that prevents the normal operation of theSSA link has been detected. The power-on self-tests (POSTs) are running or have failed. Thelight comes on as soon as the disk drive module is turned on, andgoes off when the POSTs are complete. If the light remains on forlonger than one minute after the disk drive module is turned on, thePOSTs have failed. Neither SSA link is active. The disk drive module is in Service mode, and can be removedfrom the 7133.Flashing The Check light has been set by a service aid to identify the position ofa particular disk drive module.Chapter 1. Reference Information 1-9

IBM 7133 Series Service Manual