Service Mode; Initial Service Menu - Tektronix 2246 1Y Service Manual

2. ROM diagnostics—failures indicated by flashing
AUTO lamp. Tests all of ROM, except for ROM
header. Runs proprietary version of CROC test.
3. Readout interface diagnostics—failures indicated
by flashing NORM lamp. Performs a marching-
one test around the loop from D7-D0 to R7-R0
and back.

SERVICE MODE

The service mode driver menu is accessed by
pressing the top and the bottom menu-item buttons
at the same time. The initial SERVICE MENU will be
displayed as shown in Figure 6-2. Each service
menu display has two parts; the part to the left is the
service menu, and the part to the right is the
modifier menu.
SERVICE MENU/
DIAGNOSE
CONFIGURE
SELF CAL MEASUREMENTS
INTERNAL SETTINGS MENU/
EXERCISER MENU/
Figure 6-2. Initial SERVICE MENU.
Each service menu has a title and a number of
selectable items in the menu. The title appears in
the top line of the crt display, and the selectable
items appear under the
Figure 6 -2 ). Menu choices that are names of sub­
menus have a following slash (/), and when one is
underlined, the word " SELECT" appears in the
modifier menu list. When a choice with sub-menus
i s s e l e c t e d , t h e s u b - m e n u
t MENU
4 ,
QUIT
6555-23
title, indented (see
are displayed on
c h o i c e s
Maintenance—2246 1Y and 2246 Mod A Service
the left side of the screen with the name of the
selected sub-menu displayed in the top line.
A menu choice that has no following slash is an
executable service routine. The routine may be run
by underlining it and pressing the menu button next
to the RUN label that appears in the modifier menu
list. Executable servicing selections are: diagnostics
that return either a pass message or a fail message
along with service data; one-shot exercisers that
carry out some service and immediately return to
the menu; or regular exercisers that carry out a
service while continuously displaying service data.
An underlined service-m enu choice is available for
selection. To select a menu item, use the buttons
next to the up-arrow and down-arrow symbols to
move the underline up or down in the SERVICE
MENU. When the underline is below the sub-menu
title, pressing the menu button next to up-arrow
MENU label returns to the preceding menu con­
taining that sub-menu (an up-menu operation).
Pressing the QUIT selection or CLEAR Display button
at any time the choice is displayed will cause the
scope to return to normal oscilloscope mode. If a
service routine is operating that has an END menu
selection displayed, pressing the button next to END
exits the routine and returns to the selection menu
(where QUIT is displayed). Routines that run once,
return to the selection menu when finished.
The diagnostic tests in the SERVICE MENU may be
run with a conditional setting that determines how
many times the routine is done. The conditional
MODE setting menu choice appears in the modifier
menu when the DIAGNOSE choice in the SERVICE
MENU is underlined (see Figure 6 -3 ). One of the fol­
lowing mode types will be displayed:
ONCE, CONTINUOUS, UNTIL PASS, or UNTIL FAIL
Change the mode type displayed in the bottom line
by pressing the MODE button. When ONCE is the
mode, the diagnostic is run once, and the result is
displayed. When CONTINUOUS is the mode, the
diagnostics are run continuously. When UNTIL PASS
is the mode, the diagnostics are run until they pass.
When UNTIL FAIL is the mode, the diagnostics are
run until they fail. In order to stop a diagnostic that is
looping in the CONTINUOUS, UNTIL PASS, or UNTIL
FAIL mode, press the HALT button. The diagnostic
will stop and display the current status. When the
status is displayed, press END to return to the
SERVICE MENU choices.
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