IBM 9080-M9S Manual page 310

Figure 261. Activating the identify LED for a faulty part
9. Look for the flashing amber LED of the faulty or failed miscellaneous A voltage regulator module.
Miscellaneous A voltage regulator modules are in locations P1–C56, P1–C60, P1–C65, and P1–C66.
Refer to the following image.
304 Power Systems: Removing and replacing parts in the 9080-M9S system