Fluke 287 Multmeter Teardown.
Testing video: https://www.youtube.com/watch?v=FgkD8K0Ssdc
Forum: https://www.eevblog.com/forum/blog/eevblog-1592-fluke-287-multimeter-teardown/
Teardown photos: https://www.eevblog.com/2024/01/12/eevblog-1592-fluke-287-multimeter-teardown/
00:00 - Fluke 287 289 Multimeter
02:20 - Battery/Supercap problem
02:40 - Why no live TrendPlot ?
03:40 - Teardown
07:37 - Transparent case
13:11 - Schematic
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#ElectronicsCreators #Fluke #Multimeter

Hi time for a quick tear down of this fluke. 287 True RMS digital multimeter that I scored um on eBay I hoping it would be foldy and I'll link into a second Channel video up here and down below if you haven't seen it and well, yeah, it's not foldy. It works just fine and dandy. So let's take this thing apart cuz I've never taken apart a Uh Fluke 280 series before.

We got the infrared uh window down here. haven't uh tested that and it's your traditional overmolded uh design like this. I'm not a fan of the tilting B when I first got it and I first started to use it, um, it just it just fell off. Is that normal I don't know.

they've just got uh, looks like just these little um, nobbly things here and then the and then tiling Bale just sits in there like that but that just easily comes off I don't like that at all. so I'm not not impressed by that. Have I just got a dodgy one? don't know. Anyway, the back of it all they've got is uh, two hooks up here and the and just the one, uh, one of these, um, you know, battery thumb? screw things down here and we'll lift this off and there you go.

There's our battery. uh, pack in it. uh, six, AA uh cells I did actually uh Bend uh, one of these contacts here when I actually uh first took it off. Now interestingly, they got three terminals in here I'm not sure what that's for I I would maybe for a rechargeable pack solution? maybe but then how do you charge it? I'm not sure like Cu, the extra terminal would often be like a temperature thing or something.

Anyway, we've got our two HRC fuses there. They're easily replaceable, so looks like we got two four six screws holding this bad boy in. so let's take it apart. Yeah, we may have to avoid the warranty.

We'll just slice that off, shall we? Unfortunately, the comically long screwdriver doesn't fit. Oh bummer. Going to have to get a different size. So will this have like an MSP 430 Pro processor? like uh, the other flukes do cuz fluke transitioned over to the 430 a few decades ago.

It's been a long time. Um, but I I don't know or do they need something beefier to do the big graphical uh display. One thing I am disappointed about with the um, they do have the trend thing in this ah, time and date need to be reset. Um so yeah I believe this has a super cap in it.

Um, so that might I don't know that might be might need replacing because the batteries were out while I was just shooting this intro here but wasn't for that long. But anyway. okay, one thing I wanted to show you here is let's just go into uh, record mode here. Okay, and we can record like this.

So I've got it set for 1 second. Uh, recording here and if we start that okay, it's going to sample once every second and there it goes. 2, 3, 4 and um, this thing of course, famously has uh, the graph Trend plot or whatever it is. uh, they call it.

but I Don't believe you can actually do it I have an Rtfm Rtfm. but I don't believe you can actually do it until you actually go until you stop it and then you can go Trend like that I like why is there some firmware upgrade that allows you to do it live? But anyway I find that really annoying. Anyway, I would consider that a bit of a uh fail. really.
They go to effort to have the nice Trend plot capability. Then you can't do it. live like that's just ridiculous. Come on.

Seriously, that's our last self Tapper there. So let's get the can. we get it apart. Is it just going to? It's going to do it without a fight.

or are they Clips Uh, there could be something up the top here I Sense great disturbance in the force up the top. Oh there we go. Got a spudger in there and we're in. Oh look at that.

There you go. Nice plastic work there I Rather like that and those integral uh, battery contacts there. they're Beau Beautiful. So yeah, very happy with that.

And inside we're immediately presented with this, uh, nice big shielded plastic Here this will be a conductive plastic I'll prove that to you. Get the baby fluke jobby here and there you go. There you go. 50 Oh 40 Ohms Yeah.

so conductive plastic. So let's get that off and another self Tapper There you go, we are in. Beautiful. All right.

Look at that. Wow, And immediately let's go straight down. I Can't read this on the bloody camcorder screen And yep, that is indeed an MSP 430. So there you go.

Um, and of course. uh, the graphics are processing. It's not actually doing all the graphics processing. It's probably like a that looks like a Serial interface over there.

buggering off, is it? Anyway, Um, there's our hybrid resistor Network There, we've got another uh ceramic resistor. uh Network there. That's the just the high voltage, uh input resistor there. Of course this is Cat 4 600 volts cat 3 1,000 volts So it's going to have pretty decent input uh, protection and spacing and everything else.

And we see that here. We've got the isolation slots all around here. We've got our fusible input resistor here. We've got a PTC We've got three.

Ms They're not huge, but there's there's three Ms there. Um, there's our 10 amp current shut and I'm not seeing the DI bridge for the fuse protection. Usually you have one of those could be on the other side. There's another uh PTC up here that's missing, so that's interesting.

But anyway. um, there you go and they've got a, uh, just an isolation slot under the uh input resistor uh divider there. Very nice. a whole bunch of miscellaneous stuff.

And there's our little super cap over there. Is that a super cap or a battery? I've been told it's C Yes, it's C it's got C 145 so that's actually a they're using that as a super cap there. And there's our buzzer. Um, and there's a couple of unpopulated footprints up here.

What's an EET 1 and an EET 2? Does anyone know? Is this a like some sort of expansion model thing? I don't know what? the 289? Uh, I don't know the exact difference offand between 287 and the 289. But anyway. um, that's interesting. and there you go.
We're going to have the transmit and receive leads there cuz I think you can do uh, it's you know, bidirectional. You can uh, set calibration and do stuff. Got our large pads for the battery and whatever. uh, that extra uh terminal.

there is not going to go through on reverse engineer everything. There's no point in that some nice golden uh guard traces there. If I get them at the right angle, they'll be nice and shiny. Look at that.

Beautiful. um yeah. So they guard uh traces to stop any uh uh leakage on the board. Very nice.

And of course the rotary switch down here that looks pretty Schmick this looks, uh, very different, doesn't it? um like I don't know I Rather like that. Anyway, is that dual wipe contacts down in there? It looks like it possibly is. but we can get the uh, we can get the board out and of course you can view this in I'm I'm shooting this in 4K resolution so we can actually do this like I could put this under the Tagano microscope but um, you know and then we could go around. but unfortunately, the Tagano microscope's only 10 80P it's not.

uh 4K So yeah, if you want 4K I've got to actually shoot highres photos and then uh, do my talking head screen capture I Find it interesting how the side of the case is actually, uh, transparent. It's actually a transparent plastic that they've put the rubber over mold over that so that's rather interesting. and I really like the look of these input. Jacks Here, they look pretty Schmick So I'm going to have to get those out I believe to take the board out.

but but very nice. Spared no expense. Really spectacular. Spared no expense.

All right. So let's flip this board out that just comes out. There was just one screw there, which was the same as all the other self-tapping screws. Ah, check it out.

No, no, no, no, no, no, no. we have another processor over here anyway. Oh I Like how the rotu switch is like, oh wow, You know that is different. That is different to other flukes, isn't it? That's really rather groovy how they've implemented that I Really like it.

Um, it's like a two-sided thing and there must have been a screw access from the other side which I couldn't see deep down in there so you can take that off. I'm not actually going to take that apart, but that looks pretty Schmick So anyway I was talking about the DI Bridge before. Yeah, there it is. It's on the bottom.

um I've done a video on M multimeter input protection so I can link that in but no. look. look, we have a free scale processor down here. So the MS P 430 was just doing the.

They were leveraging the MSP 430 uh Tech which they have on their existing multimeters for just doing the multimeter functionality. and then all the graphics and all the um, data loging and all the whatnots uh is done by this I can't see it here I can't see that on the screen here I'll put it up here and uh then looks like we have two memory devices and is at our flash chip so that's that's pretty grunty isn't it? This thing does have 100 hours battery l nominal uh and actually 200 hours in login mode. So I presume you know cuz it samples slower uh than in regular multimeter mode. it choose like half the power.
So anyway, that's interesting is it not? So this is a REV 15? Uh, that is that the reference? Is that our reference I Suspect that could be our reference. Just looking at that. it looks pretty important. Um, perhaps got another Analog Devices Jobby there can't read that.

On the camcorder screen. there's another conductive plate so that's sandwich between there. and look at this. Look at the key.

Look at the for the uh, keypad thing. It's like a waterproof thing with like a whole plastic clear plastic enclosure. there isn't it. Why have they gone for Clear Does anyone know? Leave it in the comments if you got any idea.

Anyway, there's the LCD there. You can actually buy uh, replacement. uh else like screens and whatnot for these. but uh, jeez, that's that's really nice.

I Yeah, there's our infrared uh, transmit and receiver there. So you right going to take some highest photos as always available on EV blog.com via my flicker account. So yeah, I'm thoroughly impressed with the construction of this thing. and what is it like a 20year old design or something like that? Just everything about this, um, screams, uh, quality.

Spared no expense and like, look at all the uh shield in here and then we've got the does that? No, that's all okay. so that's all part of the case there. So the rubber baby buggy bumper keys there. um, they're just on the front there against the uh, like transparent um, front case on that.

It'd be cool if they actually did a transparent version cuz they did release a transparent case version of the uh fluke 87 at one point. But anyway, um, there's our switch range switch down there. That's your classic implementation of your uh, fluke switch. Um, it's like a lot of people copy that too.

So yeah, it's Works a treat. I really do like the implementation of the uh, the actual mechanism itself there. that's that is really quite nice. and uh, yeah, I think there might be I can't see down in there.

but I guess there's a screen. Put a tiny screwdriver down there and you can take that off, can you? But I'm not going to. sorry. Anyway, you can see all the rest of it around here.

What of these? I can't read them but I'd be guessing uh, you know, 4051s? um, something like that? perhaps? uh, some 4,000 series uh Maxie type stuff happening. See, you guys have the advantage of being able to watch this on your big screen monitors. Uh, and you know in the Glorious 4ks and I'm like watching on this little ply 2 and 1/2 in 3in uh, camcorder screen can't see diddly Squat and we've got a little plastic sheet there so that, uh, it doesn't so that the rain switch up here doesn't rub so that's nice. Attention to detail.
so kind to put that all back together that's really groovy. That is really quite nice. This uh meter. worth every cent from a Uh design and build quality point of view, that's for sure though.

I'm surprised that they don't have any locktite on the screws holding in the connectors. That's interesting. Um, yeah, he I I'd like to see some Loctite on there, pretty please, but guess it hasn't been a problem for them I Don't know, leave it in the comments down below. but there you go.

Beautiful and just a quick one. We do actually have the schematic here. It's not for the Uh 280 series, but is for the 189 Series 2 which this one came from. They just discontinued the 189, it became the Uh 287 289 basically.

So I do believe it's pretty identical. So um, yeah, let's actually just have a very brief look. Here's our front end here, of course. So here's our uh, like there's our current shunt and 10 amp current shunt down there.

I've done videos on uh, front ends like this? There's our Diode Bridge Protection Got some extra clamp in here. looks like LM 4141 is our Uh reference there and then you just calibrate it out. So it's all about the uh Tempco um stuff. Then they've got that milliamp Jack sent in here.

and here's our input jack here. Here's our fusible resistor. We've got our high voltage resistor here. we've got our Uh PTC here.

Then we've got three mes there like that. uh, in your classic Arrangement and you know you got range switch stuff happening up here. Looks like they got some Zena uh clamping there? That's interesting. Got some more clamping action happening here.

And here's your main fluke chipset, which you saw next to that uh, hybrid uh divider Network which is actually here. That's all. that's Z too there. So those resistors are all thermally matched in the ceramic hybrid.

That's why they put them on the ceramic there and looks like they use an LTC 1968 for the true RMS output there. that's got 100 khz. Uh, well, the meter has 100 khz bandwidth. Um, yeah, there's some 4053, which I noted before.

and there's our MSP Uh 430 processor. So they're just using it like as a regular fluke multimeter. They're treating it as a regular fluke multimeter and they basically bolted on uh, the biger, badass processor on there to drive the LCD and do the uh data loging and uh, the whatnot. So you know there's some more 4053 action.

That's the Adg 714 uh marks that was on the bottom side of the board. and this is, uh, decoding the range switch here. So they actually do that using voltage. So they have a little crude ADC there and they can measure the uh, the value and know which range switch position they're in there.
And here's the main processor and it's an Mc9 3 28 and we've got the extra memory over here and we've got the ROM here. and well, that's about all she wrote. There's a for development header down there and um, yeah, they actually, um, those expansion things that's an Ethernet ethernet connector ethernet interface for development? Um, okay, made development easier, but uh yeah, it wasn't used for anything else. Then you've just got all your fancy pancy power supply stuff and uh, Bob's your uncle o LCD Drive down here.

Uh, classic. Arrangement giving you the different levels. Um for the using Lm32. Well, LP 324 is low power, not that high power.

Um LM Rubbish. Um for the LCD there. So there you go. Quick tear down to fluke 287 If you likeed that as much as I did, please give it a big thumbs up.

As always, discuss down below and over on the EV blog of forum of course where all the test equipment nerds hang out. Catch you next time! And just a pro tip, when you're putting screws back into plastic cases like this: what you do is, don't just put it in, don't just whack the screw in and then start screwing cuz you can strip the thing. What you do is you just turn it backwards like this until you can feel it drop into the existing thread and then screw it into the existing thread cuz you don't want to cut a new one, Turn it back, turn it. Oh there we go.

Got lucky and that just screws in real easy Peasy Lemon squeezy.

Avatar photo


20 thoughts on “Eevblog 1592 – fluke 287 multimeter teardown”
  1. Avataaar/Circle Created with python_avatars @jonatanrullman says:

    I have a 289 at home. The kickstand is crap. Would also have liked to see an option for external power brick because it eats batteries for breakfast.

  2. Avataaar/Circle Created with python_avatars @DavidMander-rs4uk says:

    Dad used to have something like that! He was an electrical engineer 👍

  3. Avataaar/Circle Created with python_avatars @ParthBhat says:

    It makes me wonder how you guys get access to schematic?

  4. Avataaar/Circle Created with python_avatars @offspringfan89 says:

    Great teardown. It's an amazing DMM, almost as good as my Aneng AN870.

  5. Avataaar/Circle Created with python_avatars @malithamadusankasadaruwan9836 says:

    schematic link pleaseeeeeee

  6. Avataaar/Circle Created with python_avatars @user-we4og5bz2l says:

    hello dave love your channel did you ever get the part from Germany for that gun ?

  7. Avataaar/Circle Created with python_avatars @TradieTrev says:

    For my line of work I love the magnetic clip on adapters as it makes it handy for switchboard applications to take measurements for a period of time.

  8. Avataaar/Circle Created with python_avatars @rianders1668 says:

    When will the next generation be released? Meaning Fluke 389 to follow the 289 which followed the 189.

    The 289 has been sold for over 20 years – how long was the 189 sold for by comparison?

    Improvements for next generation (389?):-

    -Make that near useless rear stand stonger and stop it falling off

    -OLED display

    -Battery life improvement OR Rechargeable Li-Poly battery pack (with Wireless Charging like a Mobile Phone) that fits in place of AA Alkaline battery holder

    -Faster boot up time

  9. Avataaar/Circle Created with python_avatars @ionelvranceanu6413 says:

    At my workplace, power electronics designer in EV, I have a bunch of Flukes with rechargable batteries. They have a dedicated charger which plugs into the bananna plugs. I don't remember exactly which of them, usually it's written on the front.

  10. Avataaar/Circle Created with python_avatars @MichaelJantzen42 says:

    Looks like the 287 supercap (made by Elna) is EOL'd – anyone know if there is an equivalent? I looked at mine and its leaking too :(. Had no idea until I saw this video :).

  11. Avataaar/Circle Created with python_avatars @lumpyfishgravy says:

    This is quite an old design dating back to early 2000s. I was involved in a contemporary job for them on the Fluke Biomed side and a bit of preferred tech came our way. I'm not surprised to see an MSP on the Meter side. I'm unclear about the ~28 pin Fluke chip, but recognize the LTC196x. It's a good part as long as you do your cals and understand its LF performance. What's that 6Hz lowpass? Could they not do that in firmware? I heard about a big-ass processor on the UI side which caused them pain ("all your engineer are belong to us"). But they got it done and made the product they wanted. I still like my 289. I also like my 189.

    I guess the transparent inner is for the IR port. The Fluke IR dongle looks weird but works fine. This was before Bluetooth took off.

    Fluke were very hot on electrical shielding. They have A LOT of experience across industries and use it well.

  12. Avataaar/Circle Created with python_avatars @mastertravelerseenitall298 says:

    If some schmoo interferes with the IR-lead-sense, use compressed air to clean it. Chemicals can stain the plastic & the IR-emitter-lens, making the DMM think there's always a probe in the ammeter-hole.

  13. Avataaar/Circle Created with python_avatars @user-py6lj9ss1t says:

    ionistor to be replaced

  14. Avataaar/Circle Created with python_avatars @MrBuck295 says:

    everything screams quality cept self tapping screws Just why?

  15. Avataaar/Circle Created with python_avatars @CarlVanWormerAE7GD says:

    Keep mentioning the "how to replace screws into plastic" comments. I often find that there are multiple paths "offered" as I reverse turn the screws where others (before me) have forced a new set of threads. I select the one the feels biggest, or I will try all paths and select the one that makes the first half-turn with the lease resistance. Keep up the good work!

  16. Avataaar/Circle Created with python_avatars @ruikazane5123 says:

    I don't know if I want a multimeter like that (because of its features AND that datalogging is useful) or not (the battery consumption thing, that bootup time and that plain garbage stand) but if one of those comes by cheap I would. Lightyears ahead of the Aneng I got!

  17. Avataaar/Circle Created with python_avatars @thedevilinthecircuit1414 says:

    Re: that clear inner skeleton: I'll bet it's polycarbonate, designed to give the ABS outer shell some beefy impact resistance. Seems odd, because usually the protective case goes on the outside. Perhaps Fluke cannot get BASF PC in the trademarked yellow color they need.

  18. Avataaar/Circle Created with python_avatars @philipp2104 says:

    just checked my 289… no rust 🙂 the ENET 1 /2 are not populated,too… so no difference there, well one thing – i only have two connections to the batterie. the "Z" connecection is missing

  19. Avataaar/Circle Created with python_avatars @orlandoalarcon4158 says:

    Si los pernos no están enroscados en metal sería muy malo

  20. Avataaar/Circle Created with python_avatars @samfedorka5629 says:

    I recently repaired one of these (289) at work where the IR LED that did the probe detection on the amps ranges had gone out. Looking on the EEVblog forums, other people have had a similar issue. Replacing the diode was easy and I appreciated the polarity marking on the PCB. Despite not having been calibrated since new, it was at most 2 counts off on all ranges. I was amazed at how much better than spec this was, with all the "normal" ranges being less than 1 count off.

    The low 50 ohms range gets a lot of use, many people reach for the 289 instead of any of the other meters.

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