Trouble Shooting To O Ls - Fluke PM3082 Service Manual

CORRECTIVE MAINTENANCE PROCEDURES
8.11 TROUBLE SHOOTING TOOLS
This family of analog oscilloscopes offers a number of possibilities to trace a fault. The tests 1 ... 4
can be done quickly and easily; however they require that parts of the oscilloscope function correctly.
The display part and power supply must be OK. Also the keys must be read by the microprocessor.
If the scope is 'dead,' you have to start with test 5.
The following tests can be selected:
1 Power-up tests that are done automatically each time that the oscilloscope is switched on. A fault
is indicated by a screen message. For information refer to chapter 8.12.1 'Power-up test'.
2 Menu-operated tests that can be done without opening the instrument. Parts of the digital circuitry
can be tested. Refer to chapter 8.12.3 'Selftest'.
3 Menu-operated tests that put circuitry in defined state. In most cases the oscilloscope must be
opened to measure the result. For this an additional measuring oscilloscope must be used. Parts
of the digital circuitry can be tested in an easy way. Refer to chapter 8.12.4 'Repair tools'.
4 The autoCalibration function is intended to automatically calibrate most of the oscilloscope's
circuitry. In case of a defective circuit part, this calibration cannot be completed for the full 100%. The
procedure is terminated then with an error number. Via a table this number indicates the circuit part
where a fault may be expected. Refer to chapter 8.13 'The autocal procedure' for more information.
5 The tests 1 ... 4 can point in a quick and easy way to the approximate fault location. To find the
defective component, you have to measure in the instrument. For this purpose the circuit diagrams
in this manual are provided with DC and AC voltages that can be measured with and additional
measuring oscilloscope. For details refer to chapter 3.1.4. 'Voltage values in the circuit diagrams'.
Where no values are mentioned, it is often possible to measure by means of comparison between
identical circuit parts. This can e.g. be used for the vertical channels, MTB/DTB trigger and
MTB/DTB sweep circuits. Of course for comparison these circuit parts must have the same input
signal and must be put in the same settings. Also supply voltages can be measured. When
measuring the power supply, you have to take care of dangerous life voltages that are present.
8.12 TESTS BUILT INTO THE INSTRUMENT
8.12.1 Power-up test
After turning the oscilloscope on, power-up tests start automatically. The tests take less than a
second. A message appears on the screen when errors are found. With no message displayed, the
oscilloscope is ready for use. The tests that are sequentially done and the associated error messages
are:
- The oscilloscope's internal control bus is checked. This is done by addressing N9001, N9002,
N9003, N8005, N6014, D9009 (unit A1), N1001, N2002 (unit A2) and N1141 (unit A6).
Message: 'NO ACKNOWLEDGE ON I2C BUS'.
- The oscilloscope's hardware configuration is tested on the units A1 and A3. On unit A1 is tested
for 100 or 200 MHz and 4 or 2+2 channels. On A3 the presence of an IEEE interface and the
amount of memories. Also is tested if the the software version corresponds with the hardware
modification level.
Messages: 'WRONG A1 HARDWARE VERSION' or 'WRONG A3 HARDWARE VERSION'.
- The communication between the front unit A4 (named 'ufo') and microprocessor A3 is checked.
Message: 'CANNOT COMMUNICATE WITH UFO'.
- The contents of the settings memory is checked if back-up batteries are installed.
Message: 'NO BATTERY BACKUP'.
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