| Electronics > Repair |
| Please help, FLUKE 8920A Multimeter Repair |
| << < (45/45) |
| daisizhou:
--- Quote from: Harry_22 on June 21, 2024, 08:36:59 am ---Try to set up zero voltage for both cases. Don't be afraid it won't get any worse. --- End quote --- Do you mean steps 1 to 8 in paragraph 4-48 on page 4-19 of the Service Manual? Adjust R72, TP3 voltage is (0mv), adjust R26, TP3 voltage is (0mv)? Finally adjust them to 0mv? Or 1mv? |
| Harry_22:
Yes |
| daisizhou:
As you requested, I followed steps 1 to 8 in paragraph 4-48 on page 4-19 of the manual,Adjust R72 and R26 respectively, and finally stabilize TP3 at 0mv. If a 50 ohm load is connected to the 8920A input interface, the analog pointer will no longer fluctuate. If the 8920a input interface is not connected to a 50 ohm load, the analog pointer will still fluctuate when the "LO RANGE ENABLE" is pressed. is this normal? After adjustment, I conducted another accuracy test. Here is the test picture: |
| Harry_22:
--- Quote from: daisizhou on June 21, 2024, 11:47:44 am --- If the 8920a input interface is not connected to a 50 ohm load, the analog pointer will still fluctuate when the "LO RANGE ENABLE" is pressed. is this normal? --- End quote --- This is Ok. --- Quote from: daisizhou on June 21, 2024, 11:47:44 am ---After adjustment, I conducted another accuracy test. Here is the test picture: --- End quote --- You need another more precise voltmeter to do this test. |
| daisizhou:
--- Quote from: Harry_22 on June 21, 2024, 03:21:57 pm --- --- Quote from: daisizhou on June 21, 2024, 11:47:44 am --- If the 8920a input interface is not connected to a 50 ohm load, the analog pointer will still fluctuate when the "LO RANGE ENABLE" is pressed. is this normal? --- End quote --- This is Ok. --- Quote from: daisizhou on June 21, 2024, 11:47:44 am ---After adjustment, I conducted another accuracy test. Here is the test picture: --- End quote --- You need another more precise voltmeter to do this test. --- End quote --- 12 hours later, I conducted the experiment again. Please see the video below. |
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