EEVblog Electronics Community Forum
Products => Test Equipment => Topic started by: Fraser on June 12, 2023, 10:58:49 am
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I have not seen this unit previously mentioned on the forum so I thought I would create a thread for it.
I have been looking for a meter that will sit on my bench and provide an easily viewed, clear, display of voltage measurements as I delve into equipment under repair. My usual multimeter of choice is my trusty Fluke 87 MkIII but it is sometimes inconvenient to position and view. I stumbled upon the Mechanic Sherlock 2.0 meter the other day and it’s novel display system caught my eye. The unit has three separate displays ! There is an OLED display on each probe plus an LED display on the main unit. The displays appear easy to read and the probe displays may be reorientated as desired for ease of viewing. What a novel unit I thought.
Further investigation of the a Sherlock 2.0 revealed that it is NOT truly a multimeter as we know such equipment. It is a specialist diagnostic tool that provides ‘only’ accurate voltage, diode forward voltage drop and continuity tests. These are common tests when diagnosing many hardware faults on phones, laptops etc. Sadly there is no resistance measurement capability :palm: .Update: June 2023 - Resistance mode has now been added to the Sherlock V2.0 :-+ This is almost like someone’s specialist solution to PCB diagnostics that has been adopted by Mechanic and marketed by them. The unit does not have a high profile on the internet since it’s release in December 2022. There are a few YouTube videos that I have watched to better understand the units true capabilities. It should be noted that the maximum recommended voltage that should be applied to the the probes is only 24V. It is a specialist diagnostic tool and not really so much a general purpose meter.
I will link to a you tube video that details the Sherlock 2.0 and shows the functionality better than I can describe.
I was suitably impressed with this specialist tool and it does meet my needs for PCB diagnostics, so I have ordered one at a cost of £36 plus postage to the UK from Aliexpress.
Strangely I could not find a user manual or specifications on line which is unhelpful ! Mechanic really need to get their act together on that front.
What I can report in terms of functionality is as follows (I will add to this once my unit arrives)
1. Display: Three 4.5 digit displays (2 OLED and 1 LED)
2. Power supply : Lithium Polymer rechargeable cell - 8 hours run time.
3. Controls : Two buttons. Power and mode. (Voltage, Diode Test/continuity and probe display orientation)
4. Charger input : Type C and may be permanently powered on the bench via this connector
5. Voltage output : 3.3V available on 4mm sockets (max current not known) Unconfirmed function Since proven incorrect
6. Probes: 2 handheld probes with displays plus Qty2 2mm plug terminated crocodile clip leads for one handed probing
7. Voltage test : Maximum safe test voltage stated as 24V. No further details known at this time. No AC capability. Accuracy stated as 0.1%.
8. Continuity test : fast response sounder to continuity - threshold resistance not known at this time
9. Diode test : Displays the voltage drop across a semiconductor PN junction or “OPEN” for O/C
10. Casing material : All aluminium - no safety earth and no claim of suitability for testing high voltages. USER CAUTION advised.
11. Update - Resistance mode is now included and it can measure up to 99.99K Ohms
Videos:
Mechanic advert :
https://youtu.be/DWZnhKj72qg
https://youtu.be/ciAsqiZI25Q
https://youtu.be/vXCR8hEHH60
User Reviews:
British reviewer :
https://youtu.be/noaF8D-frAs
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The following YouTube review has a test of the continuity threshold. It can be a little hard to understand the commentary but it is shown that below 40 Ohms the meter considers there to be continuity between the probes. There is no ohms reading. This should be considered when carrying out continuity tests on PCB’s as some circuits are low impedance and are below 40 Ohms if tested.
https://youtu.be/10PFKI4dHKk
Fraser
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The store that I bought my Sherlock 2.0 unit from…..
https://www.aliexpress.com/item/1005005117374639.html (https://www.aliexpress.com/item/1005005117374639.html)
I have no connection to Mechanic or HZY Technology Limited and there are other sellers on Aliexpress.
Fraser
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The Mechanic supplied artists images of the PCB’s. The main unit contains two PCB’s.
Fraser
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Cute device! Can you take a photo with the probes to compare size against a common multimeter probe or two?
I'm tempted to buy one or two. I'm not sure I'd find it useful as-is, but I could hack the red probe into something of my own design. I'd have to assume there are 5 wires to the red probe, unlike the black probe which could share the display GND connection with the probe tip.
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My unit will not arrive for 2 weeks but the British review appears to show a similar size probe to the Fluke probes that he briefly shows (TL175 ?).
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My unit will not arrive for 2 weeks but the British review appears to show a similar size prove to the Fluke probes that he briefly shows (TL175 ?).
No worries. I might put in an order for one today anyway. Watching the videos, it doesn't look like they are too big.
It also looks like those two banana sockets might be in parallel with the probes. That would mean the 3.3V seen at those sockets would also be seen at the probe tips, and goes back to my query about the 5 wires to the red probe.
Maybe the red probe GND is floating so it is 3.3V below the red probe tip, so that it can provide 3.3V for the display circuit. Which would also mean implementing I2C isolation circuitry, all to save 1 wire. That might also be why they couldn't get accurate resistance measurements.
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At 23:16 and again at 26:00 in the review video (YT 10PFKI4dHKk) he pulls it apart and we can see the individual wires from the probe and it looks like 5 wires to each.
- red, blue, green, white, yellow
- black, blue, green, white, yellow
So my above assumptions were wrong - which is good for my plans to hack it. A pity that he damaged his unit while pulling it apart for the review.
I've ordered one, but will likely be away for work when it arrives here down under.
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OK, my unit has arrived already. It took just over a week from ordering.
A very quick test show no obvious problems:
- Voltage accuracy seems good, but I didn't have time to check against a decent reference. The extra digit on the probes is mostly noise (vs the main LED display) .
- Diode mode works as expected. Test current was about 900uA DC, so gave different readings to my Shannon tweezers which I think uses about 100uA AC.
- Resistance/continuity mode actually works from <1 ohm up to 100k, but with a 100k 1% resistor it read a bit under 93k. Didn't expect this to work at all to be honest beyond basic continuity.
- Battery was pretty low, so it is on charge now drawing approx 300mA at 5V via USB C.
I'll probably use this for a week or so and then pull it apart for hacking to maybe make a custom voltage/logic probe. Depending on how that goes I find will likely order another couple (home & work).
Overall I'm pretty happy with it.
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Mine is languishing in Heathrow Customs clearance at the moment :( Hopefully they will release it soon.
Interesting to hear that the unit can measure resistance. In the comments section of the British review someone stated that their unit did measure Ohms. As the advertising makes no mention of an Ohms resistance mode I have to wonder whether it was found to be too inaccurate or is it a new addition to the firmware after the comments on the lack of an Ohms Resistance mode ? I had assumed that the Chinglish description of a Diode Resistance mode meant the forward voltage drop of a diode that may be considered “resistance’” by some?
Any chance of photographing the user manual ? I asked Mechanic for an electronic copy of the User Manual to upload in this review thread and their dedicated European sales manager flat ignored me…. Not great customer focus :--
Fraser
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OK, my unit has arrived already. It took just over a week from ordering.
How is the continuity speed? In the youtube video the guy shows it seems OK but he doesn't tap the probes together so its hard to tell.
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Any chance of photographing the user manual ?
Sure, see attached. I am travelling right now, but thankfully I brought the unit with me.
Apologies for the poor photos but it is hard to avoid shadows with down lights.
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How is the continuity speed? In the youtube video the guy shows it seems OK but he doesn't tap the probes together so its hard to tell.
It is OK, but I've certainly seen much better. Tapping them hard doesn't get it every time. It seems like there is a sampling delay.
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Many thanks Kean :-+
Mechanic have clearly upgraded their product since it was first reviewed. They have added a true resistance (Ohms) mode with the capability of measuring up to 99.99K Ohms (according to their specifications) if you look at the attached manual excerpt you can see the original function button annotations on the left page images and the new annotations on the right page image. A diode symbol has been changed to an Omega symbol. This is a welcome improvement to the design :-+
Regarding the continuity mode, I hope for a decent response time but it will not be a deal breaker for me if it isn’t perfect as for high speed continuity I have my Fluke 87 III to use.
I am unsure what to make of the “Mechanic” brand. I dislike the blue and yellow colour scheme of the products and they look cheap. Some products, such as Sherlock and the current injection tool are in aluminium enclosures and look like a “bought-in” product from another manufacturer and do not have the blue/Yellow brand colours. Could it be like the relationship between Snapon and Bluepoint products maybe ? The user manual is, to be honest, tragic. It shows all the usual Chinglish errors that we have come to expect of companies not willing to invest in a English speaking proof reader ! They even mention “NIXIE tube” instead of LED for heaven sakes ! We are in 2023 and still see this rubbish coming out of some Chinese companies…. Pretty much unforgivable and it looks unprofessional. Even the wording of their advertisement for the Sherlock is laughable. I reserve judgement on “Mechanic” tools but the Sherlock is the only tool from them that I have wanted to buy as it is pretty unique and looks better than much of their other kit. Since they ignored my request for something as simple as a PDF of the user manual, I am not likely to buy other kit from them. Sometimes you have to buy a piece of kit from a less than great company as there are no other available options. I think the Sherlock is such a case.
Thanks again for taking the trouble to photograph the manual.
Fraser
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Of further note…..
I saw that at least one reviewer stated that the two 4mm 2mm sockets on the side of the Sherlock could be used to power a Device Under Test (DUT) and 3.3V was measured across the sockets. That struck me as an odd idea as I believed the 4mm sockets were just duplicates of the test probe tips. I see no detail in the current manual of how the 4mm 2mm sockets are supposed to be used but have seen the crocodile clip test leads connected to them for “Red lead to PCB 0V” and “Black lead to PCB 0V” testing operations. Those make sense and look to basically permit one handed probing as detailed in the advertisements. As to powering a DUT ? I have to wonder if this was an incorrect assumption by at least one reviewer. :-//
Fraser
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The only other question that sits at the back of my mind is “how long will the probes OLED displays last ?” In the past I have worked on equipment where the OLED displays failed to black over time and use and they were a very real operational liability. I hope the technology has improved since those early years of OLED modules.
Fraser
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Well it would appear that UK Customs have managed to lose my parcel ! :rant:
I have already ordered another Sherlock 2.0 so hope that this one gets to me through the dysfunctional UK Customs clearance system.
AliExpress will not refund for 72 days so there is plenty of time for the missing parcel to be found but I am not holding my breath …… Bu**er !
Fraser
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Both of the Mechanic Sherlock 2.0 meters arrived today :-+
Interestingly, both boxes seals had been opened despite not having been inspected by Customs. Both units have the diode symbol on the front panel, so are the early model, BUT they both have the Resistance (Ohms) capability plus the new instruction manual. It would appear that the boxes were opened to upgrade the functionality …. Better that than to receive old stock with no Ohms capability :-+
I am very happy with these units :-+ :-+
Fraser
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I have just completed a teardown of both of my Sherlock 2.0 units to check build quality etc. I recorded the teadown with my camera and share the pictures here.
The teardown revealed some issues.....
1. The method of attaching wires to the two 2mm sockets is less than great and uses cut down solder eyelets and top hat insulators. Good enough for this application as little current is involved. The soldering on one eyelet was very poor and required resoldering. Another eyelet fell off due to broken copper cores in its cable.
2. The LED display was still fitted with its translucent plastic protector. No big deal but I removed it anyway.
3. The LiPO pouch cell resides behind the rear PCB but it floating within the case as no protective foam pad has been used between it and the PCB. Not great practice as the PCB contains sharp cornered components that could puncture the LiPo pouch cell.
Other points of note.....
The Sherlock V2.0 has the protective clear foil on the outer display screen and one of mine had dust under it so I removed the foil. Such foil can sometimes also cause light dispersion (blurring) with bright LED displays but it did not seem to make much difference in this case. The LED display is very bright and could actually be less bright for workshop use. No problems with it though.
The original Sherlock 2.0 design connected the two PCB's using a FFC but both of my units uses a inter-PCB connector pair. I prefer this to the soldered FFC idea. Both of my units contain version 4.0.0 PCB's.
The OEM has used a nice heavy piece of steel bar to add weight to the meter, helping to keep it in place on the workbench. This could be replaced with lead if more weight is needed. The probe cables are very flexible so do not impart too much twisting action on the meter unit.
How to disassemble the Sherlock.......
1. Remove the three self tapping screws from the end cover that contains the two 2mm sockets and gently pull the cover away from the casing.
2. Remove the three self tapping screws from the end cover that contains the probe cables and gently pull the cover away from the casing.
3. Carefully unplug the LiPo cell connector from the PCB
4. Unplug the probes connector from the PCB
5. Remove the two push button caps. These may be removed using a screwdriver pushing from below and gentle rocking off their spindles.
6. Carefully slide the PCB/LiPo assemblies a short distance towards the end with the 2mm sockets whilst pressing down on the two push button shafts to provide clearance. This provides better access to the nuts on the rear of the 2mm sockets.
7. Remove the nuts from the rear of the 2mm sockets and remove the cables that connect to them.
8. Slide the PCB's and LiPo cell towards the probes end of the casing making sure to press down on the button shafts as they clear the holes in the casing. The whole PCB and LiPo assembly is removed from the casing.
9. The two PCB's will separate for inspection or rework.
Reassembly is the reverse of the above process. DO NOT CONNECT THE LiPO cell until all other parts are assembled so as to avoid an accidental short and resultant damage. Ensure the LiPo connector is correctly orientated before attempts to insert it.
Fraser
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Teardown continued.....
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Teardown continued.....
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Thanks for the photos and disassembly tips. I'm am back at the office now after a few days of field work on penguin weighbridges.
I've just pulled my Sherlock apart as well. I did have to resort to a Wera 1.5mm Hex-Plus bit to remove the rather tight screws, and long tweezers to "release" the push buttons.
I will try to do hacking to drive the OLED from my own circuitry later this week.
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Penguin’s ? I adore Penguin’s :-+ I saw a lot of them whilst deployed to the Faulkland Islands back in 1992. Such cute little characters, but boy did their colonies smell bad, especially as I seriously dislike the smell of fish !
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Some test results from my Fluke 87 III whilst testing probe P.D. and current flow in the probes short circuit condition……
Semiconductor Junction (Diode) Test Mode
P.D. Across probes = 3.295V d.c. (Red probe is positive output)
Current flow with probes shorted through Fluke multimeter mA range = 0.950mA
Resistance Test Mode
P.D. Across probes = 3.295V d.c. (Red probe is positive output)
Current flow with probes shorted through Fluke multimeter mA range = 0.950mA
Voltage Test Mode
P.D. Across probes = 0.000V
Current flow with probes shorted through multimeter mA range = 0.000mA
As you would expect ! :)
The 2mm sockets are connected directly to the probe tips.
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Yep, the whole thing in those reviews about using the banana sockets to power the DUT was a misunderstanding. They are just another connection point for the probes to allow using banana to alligator clip leads if you only want to hold one probe.
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I have been using the Sherlock V2.0 today and I must say I find it very convenient. I have the choice of glancing at the display on the probe or the main units large display. When using my Optivisor stereo magnifier I find the probe mounted displays very easy to view whilst probing small SMD components. I also wanted the diode check beep ‘OK’ feature as my Fluke lacks this. The units design has the feel of a skilled technician wanting such a unit, designing it for them-self and then a company buying the rights to manufacture and distribute it. Whilst it is not agricultural in design, it seems “low volume” and almost bespoke test gear. The sort of design I often see on this forum…. Like the “Shorty” short tracing tool :-+ The name of the product on the PCB’s is also completely different to the name on the Mechanic branding and, to date, this unit has three names associated with it. The one on the PCB’s…. “Super-Prober”, “Spy 2.0”and “Sherlock V2.0” ;D
I am very happy with the units for the price paid. They are definitely a niche product and clearly a relatively small production run item. The hand soldering of the 2mm socket cables is tragic with heaps of sticky flux around a blob of lead free solder, but I can forgive that and will tidy it up myself.
Do I have any negative comments on the unit ? Well no, not as yet. It does what is claimed of it and works well. The continuity response is slow compared to my Fluke but this is not a big issue for me. As has been stated by Kean, this looks to be due to the processing time and design of the system. Still very useable though.
All in all, a very useful tool that will be ever present on my lab bench.
Fraser
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(snip....)
All in all, a very useful tool that will be ever present on my lab bench.
I watched all the video reviews but wondered how well those displays would appear out in broad daylight? just in case you needed to check a fuse or circuit in an automotive or marine application outdoors. :-DMM :)
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I just took my unit out into the garden and had the sun shine on its displays. In slightly overcast conditions the displays are easily read. When the sun is out and shining brightly, the displays may still be read, with the OLED displays brighter than the LED display on the base unit. At the end of the day, you are up against basic physics. Just like with a sunlight readable laptop display, you would need a lot of nits to cope with very high levels of sun illumination and then there would be a need for brightness control as the sunlight setting would be too bright for workshop use.
In the photographs, the camera was showing the OLED raster so some of the display is not seen.
Fraser
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I have owned the Sherlock 2 for a couple of months now so thought an update was due to this thread.
I have been using the Sherlock 2 for voltage testing and reverse engineering of PCB's and have found it to be a very convenient tool to use when wearing my Optivisor and working "close-in" to the PCB. I am able to quickly look at one of the probes displays as I probe around on the PCB. Unlike the bulkier probe multimeters I find the slender probes with their very sharp probe tips very convenient and the nice flexible cable is of no hindrance at all. The bright OLED displays on the probes are ajoy to view and provide fast feedback on both voltage drop (diode mode) and resistance (Resistance mode). I do note the settling time on the resistance mode is slower than conventional multimeters but for continuity checking is is plenty fast enough to show a "Zero Ohms continuity" situation. I do wish that unit provided a <10 Ohms continuity tone to aid continuity checks whilst in Resistance mode, as is the case with multimeters (often <20 Ohms for sounder activation). A variable tone continuity mode would be great but that is a luxury item.
Over the past two months I have been using the Sherlock regularly for electronics repair and a lot of PCB reverse engineering. I found the sharp probes perfect fro high density SMD probing and I used the resistance mode for a lot of continuity testing as the Diode mode tends to give too many false positives when trying to trace PCB continuity nodes. I might add that the resistance mode is better when working in proximity to my Wife and cats as the constant beeping of a continuity tester can lead to trouble....annoyed wife and very curious kitties ! ;D
Would I buy this unit again ?
Absolutely ! It is an unusual, somewhat specialist, tool that I find very useful. So useful in fact that I own two !
I have no connection to "The Mechanic" company or any vested interest in the product, I am just very pleased with what this unusual meter can do for me in my daily work. I consider the asking price for the Sherlock 2 to be very fair considering what it can do for me in the workshop. It is most definitely NOT a replacement for a general use Multimeter though ! I use the Sherlock 2 in harmony with other tools such as my Fluke 87 MkIII, Wavetek/Fluke SF10, PEAK ATLAS Pro DCA75 and a Micsig Tablet DSO.
Fraser