| Products > Test Equipment |
| FLUKE 189 DC reading problem [with video] |
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| kamcm:
--- Quote from: coromonadalix on July 15, 2019, 01:16:50 am ---I dont want to drag your post, but if you dont need time related logs gently remove it to be sure, when this puppy goes bad, you may have excessive battery current draw or an leakage on the pcb, removed mine on my 3 fluke 189 until i bought an substitute. They are known to cause some problems in the fluke 89IV - 189 and 287 or 289 --- End quote --- I just de-solder the battery off the board and clean the spot under the battery. But still having the same problem. :-// |
| coromonadalix:
Has windsmurf wrote : do you have any contaminants on the board ?? Any solder residues ?? under the rotary knob functions, is there any grease / too much grease ? Or Maybe your meter need some calibration ?? I have my oldest fluke 189 showing a strange behaviour only in ohms measurement under 10k ohms, the ohms ranges seems to works fine, but this one in a 27mhz rf section doesn't show the same values as my other 189 ??, tested all ranges with references resistors, all is ok, all input impedances are fine, but in my rf circuit i have a strange error ?? Maybe its the Fluke asic ic who as a problem ?? |
| CDaniel:
Should be tested on all functions , maybe if we know what is working right and what is not will figure out the cause . |
| kamcm:
Here is the test on every functions. Any help would be really appreciated :) ===================== AC ACV Actual 5V Measure 4.72V Actual 0.3V Measure 0.0111V AC HZ Actual 50.00Hz 49.96HZ to 50.02 HZ, keep jumping ------------------------------- AC mV Actual 300mV Measure 283.94mV AC (mV) HZ Actual 50.00Hz 49.96HZ to 50.02 HZ, keep jumping ====================== DC Actual: 10V Measure: 8.888V =============== DC mV Actual: 500mV Measure: 470.72mV ================= ohm actual: 1ohm measure: 0.06ohm actual: 5ohm measure: 0.19ohm actual: 10ohm measure: 0.38ohm actual :20ohm measure: 0.79ohm actual: 50ohm measure: 37.66 ohm actual : 100ohm measure: 88.93ohm actual : 1k ohm measure: 0.8893 kohm actual: 5k ohm measure: 4.6855 kohm ================= mA Actual : 20mA Measure: 19.856mA Actual: 10mA Measure: 10.072mA Actual: 5mA Measure: 5.214mA Actual: 4mA Measure: 4.062mA Actual 3mA Measure: 2.763mA Actual 2mA Measure: 0.076mA Actual 1mA Measure: 0.038mA =================== Actual : 100uA Measure: 101.31uA ==================== |
| CDaniel:
So pretty much everything is bad and in the low side ... the schematic for this meters I don't think it's available but you should try to find and measure the precision voltage reference and power supplies for the analog part , before condemning the ASIC chip itself ... The input protection can't explain the current measurement being off ... |
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