Klein MM1000 with a couple of dodgy resistors. - Page 1
Forum section: electronics / testgear

author: bsparks
author_rank: Newbie
timestamp: January 25, 2014, 02:57:45 am
content: So I decided to crack into my Klein MM1000 multimeter today after it had occurred to me I hadn't in the past year or so I had owned it. Well when I did I was in for a little bit of a shock, and a lot of what I expected. It's put together much like the MM2000 in this review on the forum,https://www.eevblog.com/forum/testgear/klein-tools-mm2000-multi-meter-review/. Including the rather disappointing hand-soldering.But this is a little different. I noticed the two large resistors up by the LCD panel had exhibited some rather odd flaking and it looked as if they had started to melt! Oh dear! What would have caused this behavior? And is it in my best interest to take the LCD panel and backlight off and replace the resistors?

author: echen1024
author_rank: Super Contributor
timestamp: January 25, 2014, 03:52:29 am
content: I see it is the "FINEST" heap of crap you can buy...

author: taemun
author_rank: Regular Contributor
timestamp: January 25, 2014, 04:17:00 am
content: QuoteMaybe they should have hired someone who knew something about Electronics.Yes, I'd replace the resistors.

author: ModemHead
author_rank: Frequent Contributor
timestamp: January 25, 2014, 04:35:32 am
content: Is the meter still accurate? If so, there is nothing electrically wrong with the resistors. Those resistors (in series) form the top half of the input voltage divider at 9.9 Megohms. If you were to replace them, the meter might need recalibration.

author: tony3d
author_rank: Frequent Contributor
timestamp: January 25, 2014, 07:54:03 am
content: My Klein MM1000 just crapped out on me this week. All of a sudden it just switches to volts at random. Decided to buy an Agilent U1272a.

author: Napalm2002
author_rank: Regular Contributor
timestamp: January 25, 2014, 04:28:39 pm
content: Good choice on the Agilent. I would like to have one someday.

author: tony3d
author_rank: Frequent Contributor
timestamp: January 25, 2014, 05:08:49 pm
content: Quote from: Napalm2002 on January 25, 2014, 04:28:39 pmYes, I 'm very excited! I think for $374.00 you get quite a nice package including proof of performance, and a three year warranty to boot! i love the fact that the fuses are so easily replaceable, and I just can't resist that sexy orange display.

author: nanofrog
author_rank: Super Contributor
timestamp: January 25, 2014, 05:58:41 pm
content: Quote from: tony3d on January 25, 2014, 05:08:49 pmI must admit, the orange backlight on my U1252B is gorgeous. Will definitely put aon your face.That said, I'd recommend the BM869 you've asked about, or up your budget enough to get an Agilent U1252B instead. Better specs and additional features than the U1272A from either. Fuse replacement isn't difficult IMHO at all. Granted, you'd have to turn a few screws worst case (remove rear cover), but they're captive to prevent them from being lost.

author: tony3d
author_rank: Frequent Contributor
timestamp: January 25, 2014, 07:16:44 pm
content: Quote from: nanofrog on January 25, 2014, 05:58:41 pmActually on the U1252b I think you have to not only remove the back , but the circuit board as well because the fuses are between the face and the board. The Brymen may be different. Can you elaborate on the advantages over the U1272A that the Brymen has? One feature that the U1272a has that I really like is the trigger, and auto hold feature. The Brymen requires a third hand. To me that just about justify's going with the Agilent. I really see no other advantage that the Brymen may have, unless I'm missing something. Does the Brymen come with a proof of oerformance, and a 3 warranty? I would think getting it repaired would be somewhat of a hassle as well. Please, if I'm way off base here let me know. I want to get it right this time! Just looked at a Brymen teardown, and one of the fuses is sitting right over SMD Components! Let's make it as difficult as we can shall we. I think I'm good with the Agilent U1272a.

author: nanofrog
author_rank: Super Contributor
timestamp: January 25, 2014, 08:44:39 pm
content: Quote from: tony3d on January 25, 2014, 07:16:44 pmCorrect. The Agilent is more of a PITA for fuse replacement (remove rear cover, remove board assembly from front cover, flip, and then you can access the fuses).I'd have also preferred they use AA batteries as well as easier fuse access. But you can't have everything and it be cheap.Not that it's a budget meter, but it's not as expensive as a Fluke 287/9. So I see it as an acceptable compromise (fuses done this way by many meter manufacturers for years).Quote from: tony3d on January 25, 2014, 07:16:44 pmThis was the meter I was commenting about. Sorry for the confusion.The BM857 I have, they're available once the cover is off (older unit, so I have to do this just to change the battery). Specifically, the board is attached to therear cover, not the front. So once it's off, you're looking at the front of the board, and the fuses are right there. Newer versions of the BM857 have a separate battery cover, so would require the main covers to be separated (board still attached the same way). Not too bad either way, IMHO (captive screws really help; bale comes off when 2x of the screws are loosened, so I have to keep track of that).Based on (these pics), the BM867 & BM869 appear to be the same way as the BM857. OP just pulled the LCD/range selection board from the main board, as it's a comparison thread.Hope this sorts things a bit.Quote from: tony3d on January 25, 2014, 07:16:44 pmHigher counts is THE most obvious, particularly if you engage the 500,000 count mode (i.e. DCV), followed by features, such as dual temp (I have this on the U1252B, not on the BM857, which doesn't have temp at all). Useful for obtaining the temp difference on heat sinks from ambient for example in real time (less chance there's a shift in one or the other between making separate measurements).If you're really interested, do a side-by-side spec comparison (2x browser windows or print them out), and see what's applicable to your uses.If you've questions the spec sheet doesn't answer, just ask, as I'm a bit confused as to exactly what you're looking for.I do realize there are such situations, such as the hold issue, so I'd ask you be as specific as possible.There's also a couple of threads on the BM869 here in EEVBlog that could be of real use to you, as well ashere.Quote from: tony3d on January 25, 2014, 07:16:44 pmIf this is critical to you, then the Agilent would be the way to go.But which one?Quote from: tony3d on January 25, 2014, 07:16:44 pmSee above as to what exactly are you looking for.My comments have been based on a spec & features comparison, as they're not as comparable (BM869 vs. U1272A), as the BM869 would be with the U1252B (i.e. both are 50,000 count <basic mode for the BM869>). But if there's something specific, that could change matters, such as the hold feature mentioned above.Quote from: tony3d on January 25, 2014, 07:16:44 pmBrymen doesn't come with a CAL cert, and they warranty it for 1 year, where as the Agilent will include the CAL, and is warranted for 3yrs. But rebranded Brymen units can change this. IIRC, Extech for example, offers a 3yr warranty. Greenlee sells them calibrated for an additional cost.But unless you need to be able to trace it, a DMM Check+ or similar device would be something worth looking into in order to see if it's gone bonkers or not (and it's useful for any meter, no matter what make/model).As per repair, you'd likely have to send it to Brymen (if it's their label on it). Otherwise, to the rebrand company, and they're likely to send a new unit, possibly a substitute if they've quit selling that model.

author: Wytnucls
author_rank: Super Contributor
timestamp: January 25, 2014, 09:21:46 pm
content: The 500,000 count offers a better resolution, however it doesn't improve on the accuracy of the basic 50,000 count (0.02%+2d on mV DC).

author: nanofrog
author_rank: Super Contributor
timestamp: January 25, 2014, 09:37:44 pm
content: Quote from: Wytnucls on January 25, 2014, 09:21:46 pmI should have specified this. Thanks, as it's quite important to understand the difference in this case.

author: tony3d
author_rank: Frequent Contributor
timestamp: January 25, 2014, 11:30:44 pm
content: Well, thanks for all the input guys. I still strongly feel the Agilent is the way for me to go. First off as you said their just aren't many models left with easy fuse access, and personally I think that really sucks! Who wants to disassemble the entire meter because of one stupid mistake! Second I really feel that the balance between resolution, and accuracy is perfect in the Agilent, plus I feel it's loaded with some really nice features.I took apart my Klein, and found the issue with the functions jumping all around. The knob contacts were terribly worn. This thing is only 5 months old! What a piece if shit! I don't know if I just got a bad one or what, but the strips were in terrible condition. You could see carbon on the contacts, and strip, so I'm sure the damn thing has been sparking! I learned my lesson. You get what you pay for. I really hope this Agilent will last me at least a few years. Funny thing is this meter never saw A/C in any kind of voltage beyond maybe 9-12 volts! What a piece of crap! Had I not opened it all up I would have loved to bring it back to Home Depot! Now the one thing that does bother me about the Agilent, is both Dave Jones, and Martin seemed to think that the rotary switch was just ok. I would die if this happened again to me on a near $400.00 meter!

author: taemun
author_rank: Regular Contributor
timestamp: January 26, 2014, 01:44:47 am
content: Quote from: tony3d on January 25, 2014, 11:30:44 pmProper meters will have more than 5 months of warranty.

author: rdl
author_rank: Super Contributor
timestamp: January 26, 2014, 02:59:17 am
content: $400 for a multimeter for hobby use? Seriously? To each his own, as they say.

author: tony3d
author_rank: Frequent Contributor
timestamp: January 26, 2014, 03:22:13 am
content: Always wanted an excellent meter. Life's just to short, and it's only paper!

author: Napalm2002
author_rank: Regular Contributor
timestamp: January 26, 2014, 04:24:22 am
content: TouchéI have a fluke 289 and hell, I have not even learned enuff yet to remotely enjoy all of its sexy features!