EEVblog Electronics Community Forum
Electronics => Beginners => Topic started by: Cody Turner OKC on July 12, 2018, 11:53:29 pm
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Hello everybody, I am more of a reader and watcher, than a poster, I have posted a few times in the last few years, mainly just browse all the posts.
So.. I have a few cheap multimeters, and I have been wanting a good quality, Fluke, or something along those lines, for who knows how long, I have been saving up for probably a year, no joke. So about 6 months ago my neighbor from a few houses down was selling a fluke 87 III, and I was very intrested, the payment that he wanted was to Mow, edge, weed-eat his front and back yard one a week, for 4 months, a total of like 16 some crazy times! AND I could not have the meter until i was finished, which was very sad, but even so i worked my butt off for the last 4 months doing my best, and on Monday I Finally finished, and got the meter,
I rushed home to start playing with it of course, and a few things seemed off-
Screen randomly restarting when i go into the 4 1/2 digit mode, beeper not always working, very dim backlight, etc-
but the main problem and question i have is about the fuses, so both of the fuses were shorted, I took them out went to every store that my older sister would take me to looking for matching fuses, After failing at every store I ended up buying a 20A fast blow ceramic fuse, and a 5 Amp equivalent, which were the closest two i could find to fit, now i know that they are way wrong for saftey etc, I just wanted to try and make a measurment,
so upon testing with them, WOW, the current readings were way, like 60mA off the pretty close matched value from all my other DMMs which all measured around the same, on all different values,
So, my first question is, would the maybe resistance of these very wrong fuses be the possible cause? Now i am to young to have a debit card, and ive begged everyone I know to let me order the fuses from the internet but everyone says no unfortunatly, so Ive come to accept the fact that it will be years before i get proper fuses, so i am guessing im just out of luck with using the meter for current readings on my new Fluke meter :(
could anyone tell me the resistance readings of the proper fuses so i can compare?
if i got a close enough match do you think i might be able to use it?
sorry for this long post, but ive been looking for hours now today for solutions and i am getting a headache, I am pretty torn up inside about it so I wanted to tell someone and maybe get a little help, it might seem like a small deal being just a few fuses but it was a lot of hard work and years of only dreaming to come to this, thank you very much to anyone who can assist, and have a great day!
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Also, even regular household fuses should read 0 Ohm on that same Fluke. If you get something else it is either Fluke completely out of cal, or you've got some really bad fuses.
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You say fuses were "shorted". That is the correct state for fuses to be in, a direct connection from one end to the other. Either you mean "open" (no connection, blown), or your original fuses were ok.
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You may be too young to get a debit card but being in the US you should be able to get an Amazon gift card, and there appear to be proper fuses available there.
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I reformatted it, sorry i didnt realise I was doing that while typing, so you dont think the fuses are causing the very wrong current readings, darn
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OOPS! I didnt realise I said that lol, They were open, no continuity- Thanks!
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hmm, I will put a picture, or the Specs that I can find for them soon
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The very first thing I would check is the battery since you mention the backlight is dim. If the battery is low it can cause strange behavior.
The Fluke fuses are special and they're not particularly cheap, but having the correct fuses is important for safety. It shouldn't affect the accuracy of the meter though.
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The very first thing I would check is the battery since you mention the backlight is dim. If the battery is low it can cause strange behavior.
The Fluke fuses are special and they're not particularly cheap, but having the correct fuses is important for safety. It shouldn't affect the accuracy of the meter though.
Yes, get the correct fuses. Getting a multimeter of this quality and reputation is no use if you mess that all up with the wrong fuses. Use the correct fuses and it should properly protect you from harm.
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OMG, Cody.... you worked really hard for that meter. Let's see... I suppose it must have taken you 2 hours to mow, edge and weedeat both yards. Times sixteen, that's 32 hours of hard labor. Figure 10 bucks an hour (a miserable rate for hard lawnwork) that's 320 dollars in sweat that you paid for that meter. That puts you very close to the cost of a brand-new, fully warranteed Fluke 87-V.
https://www.ebay.com/itm/FLUKE-87V-INDUSTRIAL-MULTIMETER/273312388438?hash=item3fa2b01556%3Ag%3Agr8AAOSwAC1Z673M&_nkw=fluke+87+-111&rt=nc (https://www.ebay.com/itm/FLUKE-87V-INDUSTRIAL-MULTIMETER/273312388438?hash=item3fa2b01556%3Ag%3Agr8AAOSwAC1Z673M&_nkw=fluke+87+-111&rt=nc)
I think this neighbor screwed you.
That being said... let's see if we can confirm that the meter is fully functional at least. First you really do need to get the actual correct fuses, and the guy who enslaved you should really pay for them (they aren't exactly cheap). Once you have the right fuses and a new battery in the thing, we can guide you through some performance tests.
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Put a brand new battery in it first!
Second remove the fuses if they are open, it's only for current measurements and that can wait until you have tested the meter properly. So start by closing/shorting the leads on AC, DC, DCmV and seeing what reading you get and if the meter is malfunctioning. Then check the lead resistance and do a diode test by shorting the leads.
If the multimeter has dirty probes or contacts in either the leads or the sockets it's going to throw all your measurements out so it's essential to do this. Next you can read a battery and see if you can get a stable DC measurement or a set resistance on ohms etc and get an idea that the meter is behaving.
Then blow some money on the proper fuses. Let us know how you get on.
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The neighbor actually did you a favor even though it was a bit of labor on your end. You saved the money on buying the meter. So now you have done all the work you can forget about it.
Here is a video on testing the proper Fluke fuses, you should follow my earlier advice though and see if you have other problems first.
https://www.youtube.com/watch?v=I6XCDj7m2LA (https://www.youtube.com/watch?v=I6XCDj7m2LA)
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both of the fuses were shorted
Fuses are supposed to be shorted, that is to say a short circuit, which is to say they should have very little resistance and should beep on a continuity test.
Are your fuses shorted (as they should be), or open circuit (as they should not be)?
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The very first thing I would check is the battery since you mention the backlight is dim. If the battery is low it can cause strange behavior.
The Fluke fuses are special and they're not particularly cheap, but having the correct fuses is important for safety. It shouldn't affect the accuracy of the meter though.
I put a brand new 9V battery in it and it helped a few things like the light, I am only wanting to measure small currents DC and I Will get the correct fuses as soon as i have a chance trust me!
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OMG, Cody.... you worked really hard for that meter. Let's see... I suppose it must have taken you 2 hours to mow, edge and weedeat both yards. Times sixteen, that's 32 hours of hard labor. Figure 10 bucks an hour (a miserable rate for hard lawnwork) that's 320 dollars in sweat that you paid for that meter. That puts you very close to the cost of a brand-new, fully warranteed Fluke 87-V.
https://www.ebay.com/itm/FLUKE-87V-INDUSTRIAL-MULTIMETER/273312388438?hash=item3fa2b01556%3Ag%3Agr8AAOSwAC1Z673M&_nkw=fluke+87+-111&rt=nc (https://www.ebay.com/itm/FLUKE-87V-INDUSTRIAL-MULTIMETER/273312388438?hash=item3fa2b01556%3Ag%3Agr8AAOSwAC1Z673M&_nkw=fluke+87+-111&rt=nc)
I think this neighbor screwed you.
That being said... let's see if we can confirm that the meter is fully functional at least. First you really do need to get the actual correct fuses, and the guy who enslaved you should really pay for them (they aren't exactly cheap). Once you have the right fuses and a new battery in the thing, we can guide you through some performance tests.
I know, a lot of work, but it was well worth it for how desperatly ive been wanting to get a better meter! I put a new battery and cleaned it up as good as i could, I did a bunch of checks on everything, except current without the proper fuses, I have tried knocking on his door like 5 times since! And my parents could care less to help, I cant really order the right fuses,I have no way to pay or anything, or enough money really!! but trust me I want fuses for it as bad as I wanted the meter!
I will post a picture of the fuses i got for a few dollars from home depot, that i thought maybe effect the current accuracy
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The neighbor actually did you a favor even though it was a bit of labor on your end. You saved the money on buying the meter. So now you have done all the work you can forget about it.
Here is a video on testing the proper Fluke fuses, you should follow my earlier advice though and see if you have other problems first.
https://www.youtube.com/watch?v=I6XCDj7m2LA (https://www.youtube.com/watch?v=I6XCDj7m2LA)
I put a new battery and cleaned it up as good as i could, I did a bunch of checks on everything, except current without the proper fuses, I will post a picture of the fuses i got at store for a few dollars that i thought was messing up the current readings,
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both of the fuses were shorted
Fuses are supposed to be shorted, that is to say a short circuit, which is to say they should have very little resistance and should beep on a continuity test.
Are your fuses shorted (as they should be), or open circuit (as they should not be)?
Yes I made a mistake! I meant that they were both Open not shorted!! Thanks!
I am trying to figure out how to post a image to show you guys the current cheap fuses I got
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Got it! Here are the attached images of the cheap fuses I got at the hardware store for a few dollars, unfortunatly there all I am going to have for quite some time, I am not planning to measure any AC current, only small DC currents in my little breaadboard things never over a hundred mA usually like 40mA etc! but I would rather not use them at all if its going to read wrong or be unsafe
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200A? You might as well replace them with a nail.
The problem is not your intent. Fuses protect the meter from accidents. Lets say you wanted to measure a battery voltage, but forgot to switch the meter from "mA" range. Fresh battery will easily supply 10 A and more. And you just fried the meter.
Your safety here is not as affected, if you don't do anything really stupid, like measuring mains directly.
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200A? You might as well replace them with a nail.
The problem is not your intent. Fuses protect the meter from accidents. Lets say you wanted to measure a battery voltage, but forgot to switch the meter from "mA" range. Fresh battery will easily supply 10 A and more. And you just fried the meter.
Your safety here is not as affected, if you don't do anything really stupid, like measuring mains directly.
oh wow, I thought it was 5A (the lowest value I could find for the 440mA fuse.. I know still way to high) the side says FNM-5 then written sideways says Amp, now i just saw the other place where it says 200A 250VAC, not sure why? but the package also says 5A time delay slow blow fuse, and yeah I didnt think about that, its probably better to have no fuse in it there then because if a mistake somehow got made it would mess my meter up, I was only thinking in terms of saftey, thank you
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it says 200A 250VAC, not sure why?
My bad. FNM-5 is a 5 A fuse. And 200 A is an interrupting capacity.
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If you watch the video resistance check of the mA/uA fuse is a slow blow as he says typically will show as 1K ohm. The 10A is showing an ohm or so (mines even less).
Put the correct fuses in it, and test it then. In the meantime leave them out and don't connect into the current sockets, no accidents.
A hint also never use the multimeter to test for current if you are unsure, otherwise you will just end up blowing fuses. When you know you're expecting say 100mA and want to measure the exact current then you first measure on the 10A range and see it's in a safe range to move to the mA/uA socket to get an accurate measurement.
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I would get properly rated fuses, even if they are not exactly Fluke endorsed. This will ensure relative meter safety. And your safety is ensured by not working on high energy circus.
Also, a set of Fluke fuses costs more than some decent meters. May be pick one of those up as well.
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Hi.
Well done for doing all that hard work gardening and on scoring a decent meter. :-+
If you want to measure current while you do not have fuses, put a small resistor (eg 10 \$\Omega\$) in line with the circuit. Then measure the voltage across the resistor, use ohms law to calculate the current ( I = V ÷ R )
I think the 87 has mV range which should help with resolution.
Do not forget to measure the resistance to get accurate results.
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Hi.
Well done for doing all that hard work gardening and on scoring a decent meter. :-+
If you want to measure current while you do not have fuses, put a small resistor (eg 10 \$\Omega\$) in line with the circuit. Then measure the voltage across the resistor, use ohms law to calculate the current ( I = V ÷ R )
I think the 87 has mV range which should help with resolution.
Do not forget to measure the resistance to get accurate results.
Good tip. Don't go messing with the wrong fuses.
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This is a textbook example of the bad advice given to beginners, to get something like a Fluke 87 on the basis of 'safety'. The OP has discovered that the fuses for this thing aren't cheap and out of desparation fitted random items from the local hardware store and has ended up with a 'safe' meter that's now more dangerous than the cheapest, crappiest ebay special. Even worse, say out of frustration he sells it on and it ends up back in an electricians toolbag (where it belongs) and gets used in real CATIII CATIV environments with dollar store fuses inside, I don't think need to say what may happen next.
To the OP, I'm sorry you got taken for a ride by your neighbour and you ended up with a bad choice of meter for what you want to do. If you do decide to sell it, please either fit the correct Fluke fuses or remove them and let the buyer know they are not fitted.
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Proper fuses are not too expensive (at least in the US).
I found those on ebay from a US seller:
https://www.ebay.com/itm/Fluke-440-mA-0-4A-1000V-Fuse-44-100A-DMM-44-100-Digital-Multimeter-fuses-/152636593083 (https://www.ebay.com/itm/Fluke-440-mA-0-4A-1000V-Fuse-44-100A-DMM-44-100-Digital-Multimeter-fuses-/152636593083)
https://www.ebay.com/itm/Fluke-11A-1000V-DMM-11-A-Digital-Multimeter-Fuse-87-V-88-V-287-289-179-US-SELLER-/161104330017 (https://www.ebay.com/itm/Fluke-11A-1000V-DMM-11-A-Digital-Multimeter-Fuse-87-V-88-V-287-289-179-US-SELLER-/161104330017)
Directly from China they are even less:
https://www.ebay.com/itm/322201723932 (https://www.ebay.com/itm/322201723932)
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Proper fuses are not too expensive (at least in the US).
I found those on ebay from a US seller:
The US seller is using the cheap item but $30 postage trick so not such a good deal after all. Sure you can take a gamble and buy cheap random stuff from China but are they real? Do you want to find out the hard way? Do yourself a favour and get a decent meter with cheap safe fuses you can obtain from a reputable dealer, why put yourself through the ebay gamble pain.
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Proper fuses are not too expensive (at least in the US).
I found those on ebay from a US seller:
The US seller is using the cheap item but $30 postage trick so not such a good deal after all. Sure you can take a gamble and buy cheap random stuff from China but are they real? Do you want to find out the hard way? Do yourself a favour and get a decent meter with cheap safe fuses you can obtain from a reputable dealer, why put yourself through the ebay gamble pain.
Yes for people in europe the shipping is $30 but within the US the shipping is free. And since the OP is from the US...
I thought he might want to buy local since he would have the fuses much sooner.
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Well done for working to get what you needed! That mindset will take you very far.
Regarding the fuses, I think I can help you out. Please send me a PM with your address.
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This is a textbook example of the bad advice given to beginners, to get something like a Fluke 87 on the basis of 'safety'. The OP has discovered that the fuses for this thing aren't cheap and out of desparation fitted random items from the local hardware store and has ended up with a 'safe' meter that's now more dangerous than the cheapest, crappiest ebay special. Even worse, say out of frustration he sells it on and it ends up back in an electricians toolbag (where it belongs) and gets used in real CATIII CATIV environments with dollar store fuses inside, I don't think need to say what may happen next.
To the OP, I'm sorry you got taken for a ride by your neighbour and you ended up with a bad choice of meter for what you want to do. If you do decide to sell it, please either fit the correct Fluke fuses or remove them and let the buyer know they are not fitted.
I don't see how a good meter with cheap fuses fitted is more dangerous than a cheap meter with those same inappropriate fuses. The fuses are one of the areas cheap meters most often skimp, but putting those same fuses in a Fluke does not suddenly make it *more* dangerous than the cheap meter.
Anyone who buys a used meter and takes it to a jobsite without even having a look inside first has only themselves to blame if something goes wrong. Whenever I buy used gear I always open the lid and inspect it for any sort of surprises prior to even trying to use it.
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Proper fuses are not too expensive (at least in the US).
I found those on ebay from a US seller:
https://www.ebay.com/itm/Fluke-440-mA-0-4A-1000V-Fuse-44-100A-DMM-44-100-Digital-Multimeter-fuses-/152636593083 (https://www.ebay.com/itm/Fluke-440-mA-0-4A-1000V-Fuse-44-100A-DMM-44-100-Digital-Multimeter-fuses-/152636593083)
https://www.ebay.com/itm/Fluke-11A-1000V-DMM-11-A-Digital-Multimeter-Fuse-87-V-88-V-287-289-179-US-SELLER-/161104330017 (https://www.ebay.com/itm/Fluke-11A-1000V-DMM-11-A-Digital-Multimeter-Fuse-87-V-88-V-287-289-179-US-SELLER-/161104330017)
Directly from China they are even less:
https://www.ebay.com/itm/322201723932 (https://www.ebay.com/itm/322201723932)
Please get your fuses from reputable sources.
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Well done for working to get what you needed! That mindset will take you very far.
Regarding the fuses, I think I can help you out. Please send me a PM with your address.
That is really nice of you rsjsouza.
Just love the community spirit here :-+
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Hey guys, thanks everyone for the advice, as I had said earlier up I ended up taking the fuses out due to the advice! And the problem is not that im being cheap trying to get some cheap fuses, the prob is that I am to young for a debit card or any way to order something from the internet and parents/ "family" could care less to help me with something! which is why i posted all of this to begin with, if I had the money and was old enough to order, trust me i would have some proper fuses on the way now! And wow, thank you very much to rsjsouza!
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One red flag I see is the meter as you received it had blown fuses which could mean that it was abused. If you are correct that it reads incorrectly on other ranges then maybe the fuses aren't the only problem. If you could get in touch with a local ham or technical school and explain your situation they might be willing to do a quick check to see if there are other problems.
On the fuses, definitely get fuses of the correct rating. The FNM-5 fuse you got has 2 problems-1st the 5A is way too high and 2nd it is a slow blow fuse and the meter specifies a fast blow fuse. Even a slow blow fuse of the correct rating will take longer to blow and may not protect the meter. The fuses specified are filled with a powder to prevent arcing if you blow the fuse when measuring current on higher voltages circuits.
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Manual info-
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Fluke meters are well known for being tolerant of abuse. The fuses are supposed to blow before damage occurs to the meter. They're not foolproof but I wouldn't assume there are issues just because of blown fuses. I've blown the fuses in mine a couple times too, not recently but it's easy to do if you're going back and forth between measuring voltage and current.
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The flaky behavior could have been due to intermittent switch contacts, both on the front main switch and the rear switch for the carbon tracks. Also, the carbon could have shed some, making for weird symptoms. Very common issue with the original 87, and the 87III is very similar.
I recommend De-Oxit D-100L with the needle applicator for the main switch. Do NOT spray any cleaner so as to get on the board itself.
Clean the rear carbon tracks with a dry cotton bud, or the same bud moistened with De-Oxit.
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The flaky behavior could have been due to intermittent switch contacts, both on the front main switch and the rear switch for the carbon tracks.
see
http://mrmodemhead.com/blog/fluke-83-iii-rotary-switch/ (http://mrmodemhead.com/blog/fluke-83-iii-rotary-switch/)
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Hey guys, I got the Fuses from rsjsouza yesterday, and after spending hours working on the meter I have made a new post in the repair section about the Current input issues that consist, althought all the other functions work great! Thanks everyone for the help and here is a link to the new post if you would like to follow up!!
https://eevblog.com/forum/repair/fluke-87iii-broken-current-input/
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You may be too young to get a debit card but being in the US you should be able to get an Amazon gift card, and there appear to be proper fuses available there.
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Hey guys, thanks everyone for the advice, as I had said earlier up I ended up taking the fuses out due to the advice! And the problem is not that im being cheap trying to get some cheap fuses, the prob is that I am to young for a debit card or any way to order something from the internet and parents/ "family" could care less to help me with something! which is why i posted all of this to begin with, if I had the money and was old enough to order, trust me i would have some proper fuses on the way now! And wow, thank you very much to rsjsouza!
FYI, you can get prepaid credit cards (sold as Visa/MC/AMEX “gift cards”) at Target, Wal-Mart, drug stores, etc. You just load them up with cash at the store. (At least initially, not sure about refilling.) Then you can use those online.
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Well my parents kind of take any money I have for there problems so the only money I do have is hidden and if I did that and we got a package from Amazon or something during the day while I was at school and they got it I would be dead in trouble for not giving then the money :/ but he sent me fuses and since they came from a personal letter they just threw it on my bed and didn't ask questions!
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Well my parents kind of take any money I have for there problems so the only money I do have is hidden and if I did that and we got a package from Amazon or something during the day while I was at school and they got it I would be dead in trouble for not giving then the money :/ but he sent me fuses and since they came from a personal letter they just threw it on my bed and didn't ask questions!
Oh my, you need new parents :(
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Have stuff sent to a friend's place and go pick it up from there, then you can say someone gave it to you.
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Well my parents kind of take any money I have for there problems so the only money I do have is hidden and if I did that and we got a package from Amazon or something during the day while I was at school and they got it I would be dead in trouble for not giving then the money :/ but he sent me fuses and since they came from a personal letter they just threw it on my bed and didn't ask questions!
That doesn't sound like a good situation. Is talking to them about it an option?
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No, They care about thereselfes and there bad habits and thats it, I am too embarrased to try and ask a friend to have it sent to them, I have to explain enough already about why they cant come over and why there is always problems, usually if i leave my parents alone, they leave me alone, and I am happy, otherwise they make my life terrible, thank you for the ideas though guys, you all have helped me more on this post then I have ever remembered being helped by my parents, it feels good for once, I think i figured out my meter problem to, I havent found replacments yet but im looking through boards of tear downs i have done for the diode bridge and smd diode, im on summer brake at school right now so I have lots of time!
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Man, get out of there as soon as you can, that sounds like a losing environment. In the meantime stay focused on school and do the best you can there, not to sound cliche but a good education is your ticket out of that mess.
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Yup that is very true, the kid's got a good work ethic so i'm not worried about him, i feel for him because i have friends whose parents acted the same way when we were growing up. i don't know how long you have to go before college applications Cody but work hard towards that and you will be very happy :clap:
Watch a lot of joe smith's youtube videos too. I don't know a single resource online that has more meters being destroyed and repaired with such clear and easy to digest material.
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No, They care about thereselfes and there bad habits and thats it, I am too embarrased to try and ask a friend to have it sent to them, I have to explain enough already about why they cant come over and why there is always problems, usually if i leave my parents alone, they leave me alone, and I am happy, otherwise they make my life terrible, thank you for the ideas though guys, you all have helped me more on this post then I have ever remembered being helped by my parents, it feels good for once, I think i figured out my meter problem to, I havent found replacments yet but im looking through boards of tear downs i have done for the diode bridge and smd diode, im on summer brake at school right now so I have lots of time!
That doesn't sound like a great situation. Just know that the world can seem like a terrible place at times and it sometimes is, but that it's also full of people who are willing to help you. There are plenty of incredible people who often materialise when you think things couldn't get worse. Remember that your current situation isn't the rest of your life. As other people have said, make sure to develop your skills and do well in school. Having success is the best answer to people causing you trouble.
If you ever need some help with electronics or your more general situation, don't be afraid to ask. It sounds like an already unfair situation, you shouldn't have to keep it a secret and do it all on your own for fear of people thinking badly about you. Even just talking about it could help.