HP 181A OFF, TEST LOOP: ON, Troubleshooting the Counter, Overview of the Self-TestRoutines, Table 2-4.A4 AC Power Supply Voltages

Chapter 2 Service

Troubleshooting the Counter

Table 2-4lists A4 power supply voltages, the corresponding wire color, and the tolerances.

Table 2-4. A4 AC Power Supply Voltages

Wire Color	Voltage	Tolerance
Red	+5.0 V	±0.250 V
Red	+5.0 V	±0.250 V
Black	0.0 V	______
Black	0.0 V	______
Yellow	+12.0 V	±0.6 V	2
Black	0.0 V	______
Blue	-12.0 V	±1.2 V

5After verifying the correct voltage and that all calibrations passed, proceed to the following section.

Overview of the Self-Test Routines

The Utility menu includes the following three self-test menu items:

•TEST LOOP:

•TST PRINT:

•TEST:

The Counter includes several self-tests. Some self tests are performed at the power-up of the Counter. Some of these self tests can also be invoked from the Utility menu. Other tests can also be invoked from the Utility menu, but a slightly different test is performed. For example, a power-up self test might work regardless of connections to the inputs while a Utility menu self test may require a specific signal to be connected. Some self tests can only be invoked from the Utility menu, for example, the keypad test.

You can specify that the tests should loop forever (TEST LOOP: ON or OFF) or until any key is pressed.

Assembly-Level Service Guide 2-47