IBM 704 manual Power-On Self-Test Post

Overview of the Diagnostic Tools

Power-On Self-Test (POST)

Each time you turn on the system, it performs a series of tests that check the operation of the system and some options. This series of tests is called the power-onself-test, or POST. POST does the following:

ŸChecks some basic system-board operations

ŸChecks the memory operation

ŸStarts the video operation peripherals are working

ŸDetects and initializes ISA devices

ŸDetects and configures EISA devices

ŸDetects and configures PCI devices

ŸVerifies that the diskette drive, hard disk drive, and other installed devices are working

Check the indicator lights on the front of the server and the back of the power supplies. Verify that all of the amber LEDs are off. If an amber LED is on, see “Identifying Problems through Status Indicators” on page 258. Verify that all server devices are operating properly. If a device is not operating properly, ensure that it is not defective and is installed correctly. Replace defective devices and reinstall any device that is not installed correctly.

If POST finishes without detecting any problems, a single beep sounds and the first screen of your operating system or application program appears. If no operating system is installed, the system prompts you to insert a startable diskette. Insert a diskette, and install an operating system. Follow the directions in your operating-system documentation and on the screen. Also see Chapter 2, “Installing Your Software” on page 27.

If POST detects a problem, an error message appears on your screen. A single problem can cause several error messages to appear. When you correct the cause of the first error message, the other error messages probably will not appear on the screen the next time you turn on the system.

Chapter 5. Solving Problems 215