Maintenance
TDS1000B and TDS2000B Series Oscilloscope Service Manual
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Menu Comments
Warmup Timer Ensures a ten-minute warm-up time for the oscilloscope before executing the
calibration procedure.
Stop Test Exits the front-panel test (Test FP) and the screen test (Test Screen).
5. Select Test FP to start the front-panel controls test.
6. Push each button and rotate each knob to verify the operation of all controls.
If all buttons and knobs have passed the test, pushing the lower menu button
(EXIT) exits the test.
7. If any button fails to operate, inspect and/or clean the switch keypad and the
front panel board contacts. If cleaning does not solve the problem, the switch
keypad, front panel board, or main board may be defective. Follow the
remaining steps in this procedure below to isolate the problem.
8. Replace the switch keypad and then retest the buttons. If the problem
persists, proceed to step 9.
9. Use the test oscilloscope and set the Attenuation switch to 10X on the P2200
probe to probe the front-panel cable connector at J202 on the main board
(two-channel models) or J1 (four-channel models). The table below describes
the signals you should expect to see.
Signal at J202
(2-channel models) or
J1 (4-channel models)
Description
1 FPLED_P LED latch line
6.44kHz. High with 120 ns low pulses. Location of pulse relative to
FPCLR_12_P determines which lights are lit.
2 FPCLR_12_P Clear Front Panel Scan line A
6.44kHz. Low pulsing high with 50ns pulses. Determines beginning
of a scan sequence for first half of front panel.
3 FPCLK_12_P Front Panel Clock line A
405 kHz. High with 50 ns pulses going low. Each clock after
FPCLR_12_P increments the scan location by one.
4 FPDATA_12_P Front Panel Scan Data line A
No fixed pattern. Stable when triggered from FPCLR_12_P. Pattern
depends upon rotation of knobs being scanned.
5GND 0 V (ground)
6 FPTHERMSTR_P Front Panel Temp Sense
About 2 V
DC
depending upon temperature, contrast setting, and
display type.
7 FP_PWR 3.3V 3.3 V
DC