HP 16500B - Manual (Page 123)

RAM Test
The RAM Test performs an abbreviated read/write test at various memory locations. The test
returns a pass or fail message. For RAM Test failures, first you can suspect a faulty SIMM
module, then you can suspect a faulty microprocessor board.
Interrupt Test
The Interrupt Test checks the microprocessor interrupts (interrupts 1 thorough 7). This test
returns a pass or fail message. If any interrupts are active, the test fails. For Interrupt Test
failures, you can suspect a faulty microprocessor board.
Display Test
The Display Test checks the display RAM and the CRT controller. During the RAM test, the
entire address range is checked. The CRT controller ensures that an End-Of-Frame interrupt
is generated. The test will report a fail message if either the display RAMs or the controller
tests fail. For Display Test failures, you can suspect a faulty microprocessor board.
HIL Controller Test
The HIL Controller Test checks the HIL interface circuitry on the microprocessor board to
verify that the microprocessor board can talk to the front-panel board. This test reports a
pass or fail message. For HIL Test failures, you can suspect a faulty microprocessor board.
Front-Panel Test
The Front-Panel Test checks the front-panel circuitry for correct operation and reports a pass
or fail message. For Front-Panel Test failures, verify the continuity and connection of the
cable from the microprocessor board to the front-panel board. If a problem is not found with
the cable, you can suspect a faulty front-panel board.
Touchscreen Test
The Touchscreen Test checks for light pulses between LED (light emitting diode) pairs and
returns a pass, fail, or an impair message.
The impair message indicates that the touchscreen is faulty, but the instrument can still be
operated. If two to four LED pairs of the touchscreen system are defective, then the impair
message is displayed. The touchscreen can still be used to operate the instrument, except for
the touch-sensitive areas controlled by the faulty LED pairs.
The fail message indicates that the touchscreen is faulty and cannot be used to operate the
instrument. The fail message is displayed if five or more LED pairs of the touchscreen system
are defective. If the Touchscreen Test fails, you can still operate the instrument by using a
mouse.
If a mouse is connected and the Touchscreen Test fails (meaning there are five or more
defective LED pairs), then the impair message is displayed instead of the fail message and the
mouse can be used to operate the instrument. To obtain true Touchscreen Test results,
disconnect the mouse before performing the test.
For Touchscreen Test failures, clean the screen and the surrounding area and move any
objects blocking the screen at power-up. Verify the continuity and connection of the cable
from the microprocessor board to the front-panel board. If a problem is not found with the
cable and the Touchscreen Test still fails after cleaning the instrument, you can suspect a
faulty front-panel board.
Theory of Operation
Power-Up Self-Tests
8–14