EEVblog #810 - Micsig MS310 Handheld Oscilloscope Teardown - Page 1
Forum section: electronics / general

author: EEVblog
author_rank: Unknown
timestamp: October 21, 2015, 09:05:51 am
content: What's inside the Micsig 100MHz 1GS/s isolated dual channel handheld oscilloscope?David2 also makes an appearance.http://www.micsig.com/en/product_detail.asp?id=19https://www.silabs.com/Support%20Documents/TechnicalDocs/C8051F33x.pdfhttp://www.ti.com/lit/ds/symlink/cdcm61002.pdfhttp://www.intersil.com/content/dam/Intersil/documents/kad5/kad5510p-50.pdfhttp://www.ti.com/lit/ds/symlink/tms320c6748.pdfhttp://www.issi.com/WW/pdf/61NLP_NVP12836B_25618A.pdf

author: hamdi.tn
author_rank: Frequent Contributor
timestamp: October 21, 2015, 09:40:47 am
content: They will freakout with this video. unsoldred pins and that bit a solder flapping around on the chip pins ... that's terrible.28:00 to 28:30 was really fun to watchyap everyday is not my day

author: bktemp
author_rank: Super Contributor
timestamp: October 21, 2015, 10:37:11 am
content: I am no expert for CAT ratings, but the isolations looks inadequate to me. The optocouplers seem to be IL206A made by Infineon. They are standard optocoupler rated for only 2.5kV isolation test voltage. Not the fancy ones with extra high isolation voltage ratings used in other test equipment.The metal cans around the isolation transforms are connected to the isolated gnd. The gap around the other soldering tab located in the system gnd is rather small. The micro coax cable can easily come off the connector (for example when the unit is beeing dropped) and touch the metal can. If this happens exposed metal parts (like the USB connector) are connected to the input!I doubt this unit would pass all the safety standards tests.

author: Fungus
author_rank: Super Contributor
timestamp: October 21, 2015, 10:46:44 am
content: Quote from: bktemp on October 21, 2015, 10:37:11 amSend it to joeqsmith on the TE forum. Let him zap it!

author: Rasz
author_rank: Super Contributor
timestamp: October 21, 2015, 10:54:09 am
content: Quote from: hamdi.tn on October 21, 2015, 09:40:47 amdont forget broken transformer, its rather obvious $4K price doesnt include QAI remember micsig post on the forum, looks like to this day they havent hired a single western engineer (translations, proofreading etc).I guess it is a big government project to establish a strong chinese corporate presence in another sector of the market, like Xiaomi, and they are heavily subsidized. Next step is usually tariffs to kill competition on the domestic market.8051 is very Shenzhen, at least they didnt put STC(chinese garbage bin special) in there.Edit: forgot scratched markings, this is pretty FAIL for someone aspiring to play with big boys./not impressed

author: Lukas
author_rank: Frequent Contributor
timestamp: October 21, 2015, 11:07:58 am
content: QFNs with obscure 3-letter markings are pretty much always from Analog Devices:H1F: ADA4817 FET opampHVB: AD8337 Variable gain amp

author: Towger
author_rank: Super Contributor
timestamp: October 21, 2015, 01:07:09 pm
content: Quote from: hamdi.tn on October 21, 2015, 09:40:47 amHi Dave, What was the story with the missing pin? It looked as if it was just a blanked out hole on the bottom board. The frontend board looked like a prototype with all the bodges. In 1080p I would see at least another 2 or 3 you did not point out.At least they did not goto town with the sandpaper :-)

author: electr_peter
author_rank: Unknown
timestamp: October 21, 2015, 07:17:00 pm
content: Quote from: hamdi.tn on October 21, 2015, 09:40:47 amOverall quality is not bad, but details are not finished. Connector between inductor, very poor soldering job on all input connectors - these should be built much better for a price.QuoteFour in a row! Dave is on a roll!

author: Ampere
author_rank: Regular Contributor
timestamp: October 21, 2015, 11:47:26 pm
content: What's with the connector between the DC-DC converters? I would think that you would get a lot of switching noise which wouldn't be desirable in what is meant to be a precision instrument.

author: Macbeth
author_rank: Super Contributor
timestamp: October 22, 2015, 12:05:01 am
content: I'm surprised Dave was so lenient on this one. It was laughable all the bits missing, terrible hand soldering, errant pin, chunks of solder shorting stuff out. Total bodges. I think in this case it was definitely a case of "don't turn it on... tear it apart!" because without mopping up after the very poor hand assembly it probably would have fried.I mean he tore the arse out of the UT-71 multimeter which was way better put together than this thing.

author: Macbeth
author_rank: Super Contributor
timestamp: October 22, 2015, 12:06:31 am
content: Quote from: Ampere on October 21, 2015, 11:47:26 pmI know. Up 'til then I thought good design let down by the hand assembly...

author: c4757p
author_rank: Super Contributor
timestamp: October 22, 2015, 12:11:43 am
content: Quote from: Lukas on October 21, 2015, 11:07:58 amThat specific style, too. ADI uses a very specific-looking QFN that they like to call "LFCSP" (yeah, sure guys, "chipscale"... it's a bloody QFN) that has a nice bevel to its edges that you don't see from a lot of other manufs. An analog section with a bunch of small 8-16-pin D/QFN-type devices with those beveled packages - usually ADI.

author: mux
author_rank: Regular Contributor
timestamp: October 22, 2015, 09:07:23 am
content: If you really start looking at the details, it really only gets worse. I think Dave had a miss here; this $4k instrument should have been built much, much better. This is unacceptable. This is either a preproduction prototype or a really shitty board/assembly manufacturer messing it up for Micsig.A couple of details:- Silkscreen is very hit&miss. You can see on the HD that they'reusing a very coarse silkscreen, comparable to what I'm getting on my $10 china boards- Soldering is mediocre. For instance at 13:44 you can see big differences; Q9/Q2 are two SOT23s that are correctly soldered with reflow, but Q3 has way too much solder on the pins. Right next to that is a 'D1' which obviously isn't a diode but has been replaced with a 51k resistor in the WRONG package size and bodged into place (see the crappy solder joint).- In the same image, they're using a shitty tin/nickel rigid contact connector to connect to a carbonized flex that goes to the keypad. This is just guaranteed to fail, especially in a portable (shaky/crappy environments) application. This should have been at least a spring contact type, but ideally just not a carbonized flex.- In the close-up shots with larger gold plating areas visible (e.g. 14:15) you can see dirt/tarnishing on the gold plating. This is indicative of a dirty PCB while doing the ENIG process. Either that or there's dust on it (it does look like meh quality plating though)- Thoroughly insufficient reflow time or unclean contacts on Y1 (crystal), see 14:24. The crystal looks dodgy too, almost like it's either been reclaimed or improperly stored.Just flipping through a minute of close-up footage I can see many grievous mistakes. This doesn't instill confidence. I've seen 30 year old Flukes that look better inside.

author: Rasz
author_rank: Super Contributor
timestamp: October 22, 2015, 10:42:09 am
content: Quote from: Macbeth on October 22, 2015, 12:05:01 amTrying not to burn any bridges on the first contact with company having a decent chance of disrupting hiend? or free scope?/joke

author: EEVblog
author_rank: Unknown
timestamp: October 22, 2015, 01:05:58 pm
content: Quote from: mux on October 22, 2015, 09:07:23 amIt's $1400.The $4K one might be similar, or it might not, we dont' know.QuoteI agree, they need to fix their production issues.But heck, even Keysight had huge production soldering issues with U1272A, a lot worse than this Micsig.

author: EEVblog
author_rank: Unknown
timestamp: October 22, 2015, 01:12:26 pm
content: Quote from: Macbeth on October 22, 2015, 12:05:01 amIIRC The UT-71 was crap design and crap components with ok soldering. The Micsig is quite good design, quality parts, with some messy soldering.I think I'd rather take my chances with the later. Production soldering issues aren't that hard to fix, and Micsig is very new. They'll get better.Uni-T have had a long time to get better and they are still struggling.

author: EEVblog
author_rank: Unknown
timestamp: October 22, 2015, 01:17:13 pm
content: Quote from: Towger on October 21, 2015, 01:07:09 pmYes, I miss a lot of stuff looking through the camcorder LCD screen. And generally pay little attention while editing (you get that way after a 1000 videos)

author: Rasz
author_rank: Super Contributor
timestamp: October 22, 2015, 03:40:30 pm
content: Quote from: EEVblog on October 22, 2015, 01:12:26 pmQuote

author: TheSteve
author_rank: Unknown
timestamp: October 22, 2015, 03:50:40 pm
content: The review seemed a little generous to me - you're getting soft Dave!edit:Dare I say it almost felt like a very gentle paid advertisement for Micsig.

author: mux
author_rank: Regular Contributor
timestamp: October 22, 2015, 05:10:12 pm
content: Quote from: EEVblog on October 22, 2015, 01:12:26 pm*some* quality parts, some bargain bin parts. Succeed brand dc/dcs? Noname 8051s? Crappy BNCs? Even the FPGA was arguably not really that impressive - it's 'only' a cyclone III, the cheapest version bar one. Although I have to say the update rate is impressive so I wouldn't knock too much on that.Quite good design is also something I'd contest on some details, like the oft-mentioned strange internal coax u.FL connector location between dc/dcs.However if it truly is $1400 and not $4k, this honestly isn't much of an issue. This is about bang on the kind of components I'd expect in a midrange product.By the way, I do concur that Agilent (and earlier Philips/Fluke) have had plenty of mfg issues with their scopemeters. I used to own a Fluke 99 and it had some serious display issues stemming from either bad solder joints or bad contact alignment. This was a very well-known issue and down to manufacturing. Not at all what you'd expect from what used to be an astronomically priced unit. Worst thing was: you didn't get support from Fluke when the screen went bad after a couple of years, so you would either have to get it repaired at high cost or cut your losses and sell it. This was the reason you could buy $100 Fluke 99Bs in the early 2000s.

author: Porto
author_rank: Contributor
timestamp: October 22, 2015, 09:38:22 pm
content: I had a BLOODY good laugh, thanks Dave!

author: Phaedrus
author_rank: Frequent Contributor
timestamp: October 22, 2015, 09:51:31 pm
content: That sticker in the battery compartment says? (si hui bu bao) and basically means "no warranty if torn" (or something like that)Edit: Heh, guess the forum doesn't like Chinese characters :p

author: Macbeth
author_rank: Super Contributor
timestamp: October 22, 2015, 10:03:54 pm
content: Quote from: Phaedrus on October 22, 2015, 09:51:31 pmWorse, it doesn't even allow greek characters which seems absurd to me for an Electronics forum

author: c4757p
author_rank: Super Contributor
timestamp: October 22, 2015, 10:12:09 pm
content: Quote from: Phaedrus on October 22, 2015, 09:51:31 pmdon't need none o' that yuny-code stuff to speak proper strine

author: Stonent
author_rank: Super Contributor
timestamp: October 23, 2015, 02:12:37 am
content: Quote from: TheSteve on October 22, 2015, 03:50:40 pmI kept wondering when he was going to say "Just kidding! This thing is crap!"

author: EEVblog
author_rank: Unknown
timestamp: October 23, 2015, 02:22:03 am
content: Quote from: Stonent on October 23, 2015, 02:12:37 amIt's quite a nice unit apart from the manufacturing issues they really need to fix.As an actual handheld scope, I like it.

author: EEVblog
author_rank: Unknown
timestamp: October 23, 2015, 02:23:44 am
content: Quote from: Rasz on October 22, 2015, 03:40:30 pmAs I understand it they have only gotten into test equipment design in the last few years.

author: EEVblog
author_rank: Unknown
timestamp: October 23, 2015, 02:27:35 am
content: Quote from: TheSteve on October 22, 2015, 03:50:40 pm

author: Stonent
author_rank: Super Contributor
timestamp: October 23, 2015, 02:50:28 am
content: I was excited at first, thinking this was the much assumed vaporware Micsig tablet in the video. That's what I really hope to see at some point.Dave, do you see Micsig being the next Rigol?

author: EEVblog
author_rank: Unknown
timestamp: October 23, 2015, 03:44:45 am
content: Quote from: Stonent on October 23, 2015, 02:50:28 amThey are starting off with the opposite attitude to what Rigol did, aiming for high end specs and price bracket.That's not good or bad, it's just different. I think Micsig's approach is probably riskier in terms of getting market traction and growing the company.Way too early to tell if Micsig will be able to get decent traction in the market though.It took Rigol more than decade, and many product revisions to get where they are now.

author: Orange
author_rank: Frequent Contributor
timestamp: October 23, 2015, 11:59:24 am
content: Hey,I proves my point that you should not take chineese stuff apart for a teardown video. Just use it until it breaks down, then take it apart

author: rf-design
author_rank: Regular Contributor
timestamp: October 23, 2015, 11:25:06 pm
content: What is possible under the soldered shield?The isolation circuit.I found only a single chinese patent for an isolation circuit. The patent WO2008061444A1 describe the single chinese isolation circuit useful for the channel isolation. The issued year is 2006. And I think they want to become one of the serious players of isolated scopes.

author: EEVblog
author_rank: Unknown
timestamp: October 23, 2015, 11:36:43 pm
content: Quote from: rf-design on October 23, 2015, 11:25:06 pmNice find!

author: Smokey
author_rank: Super Contributor
timestamp: October 24, 2015, 12:10:28 am
content: That 0.1in header with the pin in it is probably just a cheap way to make a polarity key so you can't install the mate backwards. They probably stuck that pin in there on purpose, and just used a header with one pin missing in that spot. That used to be more common when more things had 0.1in ribbon cables running all over the place.

author: crispy_tofu
author_rank: Super Contributor
timestamp: October 24, 2015, 10:21:19 am
content: Quote from: Smokey on October 24, 2015, 12:10:28 amYeah, that would explain why the pin had no solder on it at all.

author: PA0PBZ
author_rank: Super Contributor
timestamp: October 24, 2015, 11:14:21 am
content: Quote from: Smokey on October 24, 2015, 12:10:28 amI bet I know why there was a pin missing on one side and one extra on the other side.(hint: a side cutter)

author: SeanB
author_rank: Super Contributor
timestamp: October 24, 2015, 12:03:25 pm
content: The 8051 used throughout is nice, they probably have a lot of code for it which at least is stable and well documented. The one by the keyboard is most likely doing all the power management as well, along with battery charging and likely some of the control of the power to the channels so you can switch off unused parts. Probably uses the serial ports to communicate with the main CPU and give status messages and key data. Using on the isolated side is likely to use the same compiler and codebase, just to keep cost down and have less work for the developers. Known code, known responses and less to go wrong with it. Plus is it will be cheap, and have a lot of built in peripherals without issue.

author: hamdi.tn
author_rank: Frequent Contributor
timestamp: October 24, 2015, 07:30:04 pm
content: Quote from: rf-design on October 23, 2015, 11:25:06 pm

author: AF6LJ
author_rank: Unknown
timestamp: October 24, 2015, 07:45:16 pm
content: Quote from: hamdi.tn on October 24, 2015, 07:30:04 pmCool, I was wondering how they were doing that and I had it partially figured out.I wonder what frequency the transformer kicks in, and how they manage to accomplish the crossover from opto idolator to transformer as frequency increases, most likely in firmware I guess.Coolness.

author: hamdi.tn
author_rank: Frequent Contributor
timestamp: October 24, 2015, 08:49:44 pm
content: while it's nice circuit , will be fun to retro engineer it, i think TI have some isolated OP-Amp with large bandwidth (have to double check that ) , they are not cheap though, but i guess could do the job nicely.

author: TerminalJack505
author_rank: Super Contributor
timestamp: October 24, 2015, 09:20:37 pm
content: Are the Chinese cloning Altera parts now?

author: geartechbrandon
author_rank: Newbie
timestamp: October 31, 2015, 09:08:09 am
content: Will there be any more info about the 3D printer controller board using the TI TMS320 chip? Really curious about what is going on with that.