Note if errors are encountered with the reference disk in the drive they will be identified. See Appendix D for full listing. This is usually a case of non-IBM components added to the system.
Some examples are video adapters, hard drive controllers, and the like.
Also lock-ups are common with some video cards added to the system. If everything checks out then no problem. If you want it to run the full test without hanging the only method is to remove each card and reboot with the reference disk allow it to auto-configure and then reboot and run the reference disk tests. If the system hangs now then there is a problem with the system not related to added options, contact IBM or a repair tech promptly and try not to use the machine until it is looked at. All repairs are warranted for six months, even if it is not related to the original fault.