Fluke 8000A - Page 1
Forum section: electronics / repair

author: AirScooter
author_rank: Contributor
timestamp: March 19, 2021, 11:13:10 am
content: Hey Folks,My question is pretty simple (I think) I have recently acquired an 8000A that blinks 1900 continuously. Having no desire to use it as a Christmas Tree ornament, I was wondering if "1900" had any significance that might point me toward a repair. Unless I'm missing it, I don't see "1900" specifically mentioned in the manual.ThanksDave Lowa(AirScooter)

author: giacomo
author_rank: Regular Contributor
timestamp: March 19, 2021, 04:17:15 pm
content: It looks an overrange indicationIt says so at page 15 on the pdf "overrange indication", you can rotate this in adobe reader or another pdf reader programhttps://xdevs.com/doc/Fluke/FLUKE%208000A%20Instruction.pdf

author: AirScooter
author_rank: Contributor
timestamp: March 19, 2021, 07:26:15 pm
content: Grazie Giacomo,I hope you didn't have to stand on your head to get me that reply. I have a copy that reads right side up but must have been napping on page 15.What would you suspect is the reason for this over load message. I have nothing connected and it doesn't change when I do. If I put a resistor across the leads it still reads 19.00.Is it possible that it is simply a matter of calibration or is a resistor failing to throttle back the current somewhere in the ohm's circuitry.Thanks again,AirScooter(Dave Lowa)

author: Kleinstein
author_rank: Super Contributor
timestamp: March 19, 2021, 07:36:16 pm
content: There are several possible reasons for the overload reading. This could be a problem with the reference or the input signal reaching the ADC. Candidates are dirty switches, cold solder joints and maybe a supply problem. After longer storage it may be a good idea to operate the range switching some 10 times.It is very likely not a problem with the calibration, though the wiper of a trimmer is a possible failure candidate.For testing the better ranges are DC volts and amps to get a zero input. The ohms range is a bit more complicated.Chances are one could use a 2nd meter and directly measure at the ADC chips: the reference votlage and the votlage reaching the ADC.

author: joeqsmith
author_rank: Super Contributor
timestamp: March 19, 2021, 08:32:12 pm
content: Quote from: AirScooter on March 19, 2021, 11:13:10 amIn ohms mode, I would expect it to blink 1900 with nothing on the input. Do any of the modes work?

author: AirScooter
author_rank: Contributor
timestamp: March 22, 2021, 12:25:49 pm
content: Thanks for the reply JoeqI need to make my question clearer. All the voltage modes seem to work and are well calibrated.I have cleaned the switches well. The off/on button is still a little sticky but I think that if I spray it while the unit is inverted I might get to what I feel is probable grease.The display lights bright and clear all segments light. All voltage ranges able to show both plus and minus.With nothing between the leads the Ohm response is 1900 in all ranges. With anything between the leads the output is 0.00.I believe that the ohms response is indicative of something open somewhere. Am I correct in that assumption?Thanks againAirscooter