Maintenance—2246 1Y and 2246 Mod A Service
Table 6-5 (cont)
SERVICE MENU Selections
Menu Item
Action
EXERCISE LEDS
Uses the delay control to check for adjacent-row or adjacent-column
shorts in the front panel board and for inoperative LEDs.The exerciser
displays the circuit number and illuminates each LED as the control is
rotated. Circuit numbers DS2016, DS2017, DS2018, DS2019, DS2024,
DS2040, and DS2049 do not correspond to any LEDs on the front
panel. Pressing END exits the excerciser.
EXERCISE SWITCHES
Shows the circuit number of the latest m om entary-contact button pressed,
or the name and position of the latest rotary switch turned. Pressing END
exits the exerciser; pressing CLEAR MEAS’ MT terminates the Service Pro
gram.
EXERCISE DACS
Attaches the DAC (U2302, Diagram 11) to a single sam ple-and-hold
channel (through U2303), and outputs a sawtooth waveform to that
channel. Select the channel by pressing STEP. This excerciser may
be used to trace a sample-hold value through the system, with the
DAC system operating in a non-multiplexed mode. Pressing END
exits the exerciser.
EXERCISE PORTS
Continuously does analog-to-digital conversion on a single A -to -D port.
Select the port by pressing STEP. The exerciser may be used to trace
a single potentiometer wiper value or probe code value through the
system by operating the A -to -D converter in a non-multiplexed mode.
Pressing END exits the exerciser.
SHOW READOUT
ROM HEADER
Shows the Readout ROM part number (U2408, Diagram 9) and its
expected and actual checksum.
EXERCISE RO
INTERFACE
Continuously echos a m arching-bit value across the readout interface.
This exerciser may be used to check the integrity of the Measurement-
Processor-to-Readout-Processor communication system. Pressing END
exits the exerciser.
SHOW SYSTEM
ROM HEADER
Shows the system ROM part numbers (U2519, Diagram 8) and checksums
of the installed firmware version.
EXERCISE TIME REF
Steps through the timing frequencies used to characterize the horizontal
timing accuracy. Calibration periods are shown in the following table.
Time
Test Period
5 p.s
32 jis
10 )j.s
64 |j.s
20 jis
128 (xs
50 (is
256 |j.s
.1 ms
512 )j.s
.2 ms
1.024 ms
.5 ms
2.048 ms
1 ms
4.096 ms
2 ms
8.192 ms
5 ms
32.768 ms
6-14
Summary of Contents for 2246 1Y
Page 13: ...2246A Service 7062 01 X The 2246 1Y or 2246 Mod A Portable Oscilloscope ...
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Page 304: ...A D D J U N 1991 ...
Page 311: ...2246 1Y and 2246 Mod A Service WAVEFORMS FOR DIAGRAM 1 0 V r l III B f e I l i 6555 39 ...
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Page 347: ...BEV JUNE 1991 7062 18 ...
Page 349: ...2246 1Y and 2246 Mod A Service WAVEFORMS FOR DIAGRAM 6 6555 43 I ...
Page 355: ...I BOARD LOCATION 8K 8J 8H 7H 8H 8H 7J 8D 7H 8H 8J 8J 7K 8K 10D 6L 6K 6L 6K 6G 5H I ...
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