EEVblog Electronics Community Forum
Electronics => Repair => Topic started by: jimthegreek on July 04, 2018, 12:20:23 pm
-
I have a fluke 8024b meter and I am finding the dc voltages are somewhat off. I am trying to calibrate it according to the manual by providing 200mv from my power supply. There is an adjustment pot for this (R6) but it does not allow adjusting at all. I measured the resistance of the pot and it looks good.
Any ideas on how to proceed?
thanks,
Dimitri
-
Check the electrolytic caps.
https://www.eevblog.com/forum/repair/fluke-8024b-won_t-zero/ (https://www.eevblog.com/forum/repair/fluke-8024b-won_t-zero/)
https://www.eevblog.com/forum/repair/fluke-8024-repair/ (https://www.eevblog.com/forum/repair/fluke-8024-repair/)
-
Thanks! It does look like the second electrolytic cap will also need replacing. Do you know where I can find the interconnect cable between the two boards? Mine is cracked and some pieces fell out. Thanks.
-
They crack when the electrolyte leaks out. There will be board damage as well. Needs to be thoroughly cleaned with IPA and dried after caps are changed. There are lots of high impedance points where electrolyte and dirt will cause readings to be way off.
I doubt you’ll get a replacement cable unless it comes from another meter. I had some luck with mine as it was only slightly buggered. I cleaned it up and put it in the other way round.
-
One other thing to consider with all these series Flukes is if your 9V battery seems to go flat quicker than you expect in a fully functioning meter it is likely the DC jack has gone electrically 'leaky' from some form of contaminant, causing micro amps to flow even when the power is supposed to be off. I have now fixed an 8024 and a few years back an 8062 that had this issue. Both due to contamination around the DC jack.
The 8062 was fixed with a good clean but the 8024 actually got much worse from micro amps to milli amps leakage :o. so needing surgery to remove the jack altogether.
Note this may or may not be electrolyte contamination as the 8062 had its caps replaced years prior to the battery starting to go flat. The 8024 has no cap issues as there are no electro's near the DC jack. So most likely years worth of environmental crud build up.
-
Do you know where I can find the interconnect cable between the two boards? Mine is cracked and some pieces fell out.
See modemhead's document on this subject.
http://mrmodemhead.com/blog/gallery/fluke-8024b/ (http://mrmodemhead.com/blog/gallery/fluke-8024b/)
The captions in the picture explain everything.
-
Thanks for your reply. I may consider soldering the first five contacts and cut the corresponding ribbon out. Then place the ribbon back. the ohmmeter shows the remaining connections are fine on the ribbon cable. Im not sure yet if I want to invest in buying a meter from ebay for the part. What do you think?
-
I would try to DIY fix first. If modemhead were around right now, he would have better suggestions on how to repair.
-
Thanks! I will do that.