Service manual

Service Manual
Break and Escape key stuck sub-test
If the Break or Escape keys are stuck down, the
following message will be displayed on to the screen:
THE ESCAPE OR BREAK KEYS ARE STUCK
DOWN. REPLACE THE KEYBOARD
The keyboard is faulty and should be rejected.
If everything is normal and no keys are stuck then
nothing is displayed on the screen and the program
passes straight on to the next sub-test automatically.
Reset button sub-test
During the tests you will be asked to press the reset
button. This will test the operation of the switch. If
everything is normal then the program will move to the
next sub-test automatically.
Stuck key sub-test
During this test, any keys or mouse buttons which are in
a permanently closed position (ie stuck down) are
displayed on the screen. The screen display will clear,
and the following will be displayed:
SOME KEYS ARE STUCK
Note the keys that are stuck, reject the
keyboard or the mouse.
Press the Break key to continue and wait.
Press the Break key; the program will now exit to the
Keyboard/Mouse report screen.
If everything is normal and no keys are stuck, then there
will be no screen display from this sub-test and the next
sub-test will start automatically.
Keyboard LED sub-test
This test checks that the LEDs on Caps Lock, Scroll
Lock and Num Lock are working.
The screen will clear and the following will be displayed:
CHECK <caps lock> LED is ON
1 Check that the caps lock keyboard LED is the only
LED on, the other two are extinguished.
2 Press the Break key and then check the caps lock is
extinguished, hence all keyboard LEDs are off.
3 This test is repeated for the remaining two keyboard
LEDs, the display giving you suitable prompts. Note
any LED failures before continuing on to the next test.
This is a subjective test.
Main keyboard sub-test
The display is cleared and the main keyboard matrix is
displayed with the words
Main Keyboard Test
at the
top of the screen.
Press each key in turn, starting at the bottom left (Caps
lock) moving across to the bottom right (Ctrl) key, then
up a line to the left hand Shift key.
As you move across the keyboard pressing the keys in
the correct order, the key that is pressed should
disappear from the display. The test continues in this way
until all the keys up to the function key F12 have been
tested.
If the wrong key is pressed nothing will happen. If two
keys (the correct key and one other) are pressed this is
highlighted in the same way as in the mouse test. If a key
fails to disappear after three attempts, the program will
display a failure message at the top of the screen, and
then prompt you to press the Break key.
The program will now exit to the Keyboard/ Mouse report
screen.
Numeric keypad sub-test
The display is cleared and the cursor and numeric key
matrixes are displayed. The two key matrixes are tested
separately: first the cursor keys, then the text editing
keys, and then the Print, Scroll Lock and Break keys.
Finally the numeric matrix is tested, starting with the 0
key and working along the matrix in the same pattern as
before, finishing with the # key.
If you press the wrong key, nothing will happen. If you
press, two keys this is highlighted in the same way as in
the mouse test. If a key fails to disappear then after three
attempts, the program will display a failure message at
the top of the screen, and then prompt you to press the
Break key.
Press the Break key to continue.
If everything is normal the program will automatically
move to the keyboard/mouse report screen display.
Keyboard/mouse report screen
At the end of a successful test the following will be
displayed:
REPORTSCREEN
DIGIMOUSE SUB TEST - PASSED
RESET BUTTON SUB-TEST - PASSED
KEYS STUCK SUB-TEST - PASSED
KEYBOARD LED SUB-TEST - DONE
MAIN KEYBOARD SUB_TEST - PASSED
NUMERIC KEY PAD SUB-TEST - PASSED
THE MOUSE TEST HAS PASSED
THE KEYBOARD TEST HAS PASSED
Press 'A' or 'a' to test another
keyboard or
space bar to continue test suite
software.
This indicates the end of the test.
Note: The indication that the keyboard has passed is
referring to the non-subjective test elements and should
not be interpreted as an overall PASS, since you may
wish to fail the UUT on the subjective test element.
Note: During the soak test neither the keyboard nor the
mouse tests are executed.
Part 4 - Fault diagnosis Issue 2, June 1991 4-13