USB Tester surprises that can go wrong
HTML-код
- Опубликовано: 21 авг 2024
- Modern USB-Testers have lots of extra ports and their use and internal wiring often not properly documented. There are a few easy traps when it comes to using and connecting common USB-testers like the UM25 or UM34 and clones which I reviewed earlier. In this video, I’d like to address a few of these in the hope to avoid disappointment or possible damage to your equipment.
I would like to commend you on your informative videos, the presentation and attention to detail is superb. It is a pleasure to watch and grasp the points you make, some are obvious once pointed out, but escaped me during my casual usage of these meters.
Instablaster
I am glad that most devices contain the MAGIC SMOKE so that we will know when the device is becoming unusable!!! I use a very simple and cheap ($5) USB monitor, but I will now keep in mind that its use is not free, as it takes away power from the charge cycle. Thanks for this video!
Happy 50th! Great video and as usual very well explained, understanding the shortfalls of these devices is a must, the last example should be a wake up call. Merry Christmas
Excellent in every respect. Every possible question you could ever have, answered! And loving the humour. Brilliant
The two voltage levels are handy. 3V sounds about right for many modern microcontrollers.
The last example is quite scary since I would not expect a different voltage on USB devices. Well, now I know better.
Why wouldn't you expect a different voltage it? The WHOLE idea of QC and PD "Fast Charging" is to increase the voltage to increase the charging power.
Fantastic easy to follow explanation of these testers, well done and thank you.
Thank you so much for this video! I wish I had seen it back when you made it.
Well demonstrated, a lot of useful information here. Thanks for the video, thumbs up!
I always had this doubt. Thank you for this amazing class. Subscribed without you asking.
I have a tester which reports its own consumption, so always see some even with no load. It can accept an external power source though. The power source is selected via slide switch.
Unsure how good the tester is otherwise. Cheap electronics!
Hi Richard,
That is rather unusual. Out of curiosity, what make and model is your tester?
@@TheHWcave I'd say it was a cheapie looking at it. It's this one.
www.amazon.co.uk/gp/product/B07P2J5VTT
The last point is also a risk with multi socketed power banks. The one I use warned against it in its instructions (for those that read instructions). If a device on one port negotiates higher voltage then the other port will also see it. A second power bank I have will only allow negotiation of higher voltage on a separately coloured port. I've not measured the black port when the green port is running at 9V. Perhaps I ought to, to see if it does power them separately.
Hi Richard,
I totally agree with you. Multiple powerbank sockets used simultaneously are something to be very cautious about. Luckily so far the cheap ones (where the 2 sockets are in parallel) don't implement higher voltages and the more expensive ones (hopefully) do it properly. I just tested my XIAOMI 10000mAh and it won't go to higher than 5V if the 2nd socket is in use. If socket1 was 12V and you plug in socket2, it briefly turns both off and then back on at both 5V. That is not quite what you have in mind, i.e. truly independent ports, but it is a safe implementation. Hopefully other manufacturers implemented similar interlocks. It is certainly something one should test, as you pointed out.
Omg, thanks for this comment. This is nothing that have ever occurred to me that it could happen..
I have a question. I am on the search for buying a usb meter for measuring capacity of a phone's battery which uses micro usb port.The charger is a ~ 5,2 Volt one, will the capacity be shown from the usb meter correct? Cause as far as i know the batteries on phones charge at lower voltage, about 4.3 V. So wouldn't be right to say that in order to keep the same power in and out the phone the current flowing in battery should be higher, therefore the true capacity of the battery be higher than the one measured by the usb meter? Thanks for the work you put on these videos man, i didn't expect i would actually found someone actually posting so much info on this subject, really helpful !!
You are totally correct. Capacity measurements of the batteries inside a smart phone or USB power bank from the "outside" are usually reading too low. The reason is that capacity only looks at current and assumes that the voltage is identical with the battery voltage. This was true 12V lead acid batteries when capacity became "a thing". but not now with all these DC-2-DC converters in between. We should switch to energy measurements instead that takes voltage into account. I made a video about this ruclips.net/video/u-HKEb1DIWw/видео.html
thank you. very informative. looking forward for your next video
Great video. I would love to see a similar test of the TC66C device.
Hi Bruno, I ordered one but it has not arrived yet. So, yes, eventually there will be a test of it
Very well done.
Woooaa... Right at the end did the power bank just output the 9V or where did it come from? I didn't hear any negotiating... (I really like your video. Good job)
Sorry for the late reply. Plugging the phone in caused it to negotiate a higher charge voltage with the power bank. Whether that happens or not depends on the capabilities of power bank and phone but most modern power banks can supply 9V or even 12V when asked nicely using the PD protocol.
I blew up my laptop under the exact circumstances described in the last scenario ... you would think it doesn't straight pass 9V through to the PC interface used for connecting to the computer software ...
Sorry to hear that. Yes its a real danger
great video!
Any ideas for a stand-alone USB-C tester? Like, Plug in the tester in a benched Laptop and verify the port is good? That way a tech will not find out the hard way when smoke is coming from the NVMe enclosure when attemptint to re-image said laptop?
What would happen if you connect a source to the USB-C output and a sink to the USB-C input?
The end of the universe as we know it? Good question! I had to test it because I normally use the TC66C (see my videos) for all my USB-C work. The UM34C has no USB-C out (despite the label). On the UM25C, if USB-Cs are swapped, power still gets through and the display shows the voltage but current is shown as 0 despite current flowing. I also noted that regardless whether USB-C in and out are connected correctly or not, the UM25C is sensitive which way around the two USB-C connectors are plugged-in. There is a 50 percent chance the display stays dark and no current flows from source to sink. Flipping either one of the connectors on the UM25C and everything works. It has to be on the UM25C, flipping on either source or sink side makes no difference. When discussing the TC66C , I did a deep dive into USB-C and indeed the connectors / plugs are not truly symmetrically wired. However most devices take care of that, so orientation of the connector normally does not matter. In the UM34C it does matter. Interesting! I did not know this about the UM25C , so I thank you for raising the topic.
@@TheHWcave Thanks for the answer. The reason I asked because I have on of that black X shaped usb tester and I plugged it in reverse to a power bank, frying it.
I just use it for a reference tool and not to calibrate things so accuracy is not important.
Can any of these testers identify usb ports, i.e., will it identify a 3.0 port, a 3.1 port, a SuperSpeed port, a 10 Gbps port, a 20 Gbps port?
No they can't.
That AVHzY CT-3 uses an additional mikro USB Port for powering the display which is really nice when you want to test the capacity of a powerbank. I also believe it uses a hall sensor inside, very little shunt. When i plug a cheap USB-C tester in front of my AVHzY will it show the same data? For example i put my AVHzY and its internal load module to 20V 1.5A, connected to to USB Power adapter with 30WAtts. What happen when i plug another USB tester in front of it? Like Power Adapter 30 Watt => cheap USB Tester => AVHzY ? The reason i am asking is someone said the internal load mudule of the AVHzY CT-3 is only connected the to its USB-A port but not to its USB-C "in". I doubt it but how can i check it? On the screen it clearly says 20V 1.5A when i plug it to a power adapter and trigger the fast charge function to 20V and the loead module to 1.5A. It would be also interesting to see how much current the CT-3 needs without a plugged in external power supply over micro USB Port (PC port). And how much it needs with an external power supply
sounds to me the easiest way to answer these questions is to get need another USB tester (doesn't need to be fancy)
Congrats to the 50th Video.
thank you for your test , it you can't the load, the voltage compare is useless .. there are many place have resistance , so there is voltage drop
you need to adjust your measurement formula to compensate the current draw by the tester itself
@@MohamadHanifAzrai That would be terribly inaccurate, because the tester's current draw fluctuates. You need to either allow power from an external source isolated from the other ports or measure the internal current draw by using a shunt resistor placed at the input.
Danke
Hello Sir, Which is better FNB38 or UM24/UM25/UM34 ???? Does UM's have QC/PD Trigger function ?? Any suggestion on best USB tester with Trigger under $20 ?
Thank You😁 Subscribed ❤️
I have not tested the FNB38 but from the spec it looks as if it has way more capabilities than any of the (older generation) UM25/UM34 testers. I have tested the newer TC66 which can trigger but it is USB-C only (you would need adapters for other sockets). The TC66 impressed me with its accuracy which is as good as a 5 1/2 digit multimeter but its slightly more than your limit ($26)
My USB tester works at 3volts
Good to hear. The threshold when it stops working depends really on the model of the tester. I also found that when the display shuts down, the processor may still work for and can tolerate even lower voltages. You should however test if the measured values are actually still correct at very low supply voltages. The problem is that the reference voltage for the AD conversion might no longer be correct and cause measurement errors to creep in.
First 2 minutes, you are talking about USB tester not displaying the 18.5 mA that it draws like its a bad thing.
Using common sense, of course I dont want USB tester to show me its power consumption, I want the USB tester to show me how much power the device I connect to it draws.
Same as for scale, I dont want the scale to show me how much it weights, or how much a plate I put on to it weights after I press "tare" button , I want it to show me how much sugar I put on the plate weights.
I guess I will have to watch the video few times, but is there something I am missing here ? Maybe I just need someone to spell it out for me
The point is that it draws 18.5 mA without telling you about it and that means any battery capacity measurement is wrong by that amount. The battery has to power both, the actual load (which the USB stick shows) and the USB stick's own power draw, which it doesn't show. In your weight example, this would be equivalent to a scale that adds 18.5 grams to everything you weigh but doesn't tell you about it.
@@TheHWcave I see what you mean. I assume this is the only situation where USB's power draw matters and should be taken into the account ?
But I was, just to clear for all who read, talking about device connected INTO the USB, on the end of it.
Because my goal is to measure, for example, how much current the LED light draws, like you did show at 2:11.
And in that situation, power draw from USB device doesn't matter.
But what about simply connecting discharged battery to the USB tester.(instead of discharging it and measuring while it discharges)
So like this
1(5v power adapter) - 2(USB tester) - 3(battery) and measuring how many mAh is pushed trough the USB tester.
In this case the USB tester would not draw power from battery at all.
I'm not sure can capacity of a battery even be measured like this, while charging.(don't have much knowledge on this tbh)
Using some logic, it should, yes ?
@@kruskotv1311 Yes in that case the power draw of the tester would be covered by the charger. The best option is to use a tester that can be powered externally so it doesn't need to steal power from either end of the USB connection to the thing you want to measure.
I am not much of an electrical engineer, so this video is mostly above my head. I need to test a bunch of power banks at work. I bought a couple of testers and a USB load with a fan. One testster is pretty simple, like your unity, another one is more complex from Makerfire. The latter at some point went up to 40c and had it's usb connection (from the side of the load) melt. I had this happen to two testers now, but the simple tester works no problem. I am testing the power bank at 5V 1Amp, what am I doing wrong?
40 deg C isn't enough to melt plastic or solder. Something else has gone wrong here but it is difficult to understand what you were doing in each case. You are saying that you used the same setup, cables, load, power bank and with one tester it works, and the other one melts? What current were the testers showing (while working)?
@@TheHWcave yes, identical conditions, one tester (simple one) works fine, another tester (makerfire with LCD display) dies within 20 minutes. Maybe 'melt' is an exaggeration but the USB port has a bad smell coming out of it and no longer functions. The tester itself is alive, if I reconnect it to the power bank the display turns on and shows the voltage accurately, but the USB-in does not work anymore.
The current is 1.12 amps.
@@Jimmy_The_Goat My only guess is that there was a bad solder joint or contact within the makerfire tester that caused so much of resistance and voltage drop that it overheated. It may be fixable if you open the tester and examine the solder joints (and PCB tracks) around the USB port.
@@TheHWcave And what would I do to fix it?
@@Jimmy_The_Goat Difficult to say without seeing it. Check for anything like solder joints around the connector that look brittle or cracked. Anything that looks different from how the other connectors are. Then go over those with a soldering iron and reflow the solder. See if that fixes it. If the melt happend inside the connector itself you would need a new one but replacing a whole connector is more work than the tester is worth.
Can these USB 3.0 testers measure power usage by an external hard drive without interfering with data flow?
A very good question! My only USB 3.0 disk is not powered through USB, it has an external power supply instead. However, I just did a test data transfer using a USB3 cable and a USB 3 port on my computer first without and then with a UM25 in the cable. With the UM25 in the loop, the copying of a 1.1Gb file took 3 times as long (I used different files of same length to avoid wrong results through caching). So, data flow works fine through these USB testers but because the BM25 actually isn't strictly USB3.0 and implements only D+ and D- and not the additional data lines of USB 3, all transfers drop to USB 2 speed. If transfer speed is an issue, you need to look for another tester that fully implements ALL data lines of USB 3. Regarding power, the UM25 will support up to QC3.0 so higher voltages and higher amps to power a disk directly from USB should be no problem if your computer can provide it, of course.
@@TheHWcave Do you know if UM34 has all the USB 3.0 data lines?
Unlike the UM25, the UM34 has proper USB-A connectors (blue) with the additional pins and the manual states it supports USB 3 on those ports (but not on the USB-C ports which are only 4 wires). To confirm I tried the same transfer test explained earlier but it failed after a second or so with an IO error. Now, I am pretty sure that this is NOT the fault of the UM34 because the 3.0 sockets on my PC are worn and not very good in making reliable contact anymore, especially if a tester is literally "hanging" on them. I sometimes get such errors even without a USB tester. Unfortunately at the moment I have no other way of testing so I can't confirm 100% that it works.
Gibt es diesen Kanal auch auf Deutsch?
Ich verstehe englisch sehr gut, aber für sehr technische details fällt es mit viell leichter in deutsch zu verstehen.
Ich vermute, das sie auch deutsch verstehen ;)
Leider nicht aber die Untertitel sind mein original Script und daher sehr detailliert vielleicht geeignet über Verständnisprobleme hinweg zu helfen. Es ist möglich die Untertitel automatisch in Deutsch zu übersetzen. 1. Enable Subtitles. 2. Click Settings. 3 Select Autotranslate 4. Select German
can you try this test with fnirsi usb testers ?
ok after i type my comment i noticed ur video was uploaded 3 years ago
Sadly I don't have any fnirsi usb testers. If I ever get one, I will test it of course.
How did you build the USB by USB black tester box to connect to the meters
I did a small mod and showed the inside in this video on repairing a power bank
ruclips.net/video/LSrtbNV9vt4/видео.html
(I should really start numbering my videos to make these references easier...)
The box is incredibly simple and easy to make and well worth having. I should probably make one for micro USB as well...
@@TheHWcave instead of making another separate USB black box tester with microUSB support, Would it work if you simply connected a microUSB adapter to your existing box?
Great vid thanks!
@@SS-pi2yi Yes of course. I do that myself.
What USB tester would you recommend? After all is said and done.
It really depends on your needs. If you are doing mostly USB-C get the TC66 and use adapters for other USB types. The TC66 is amazingly accurate and can be externally powered. If USB-C is not your thing any of the testers in that video will serve you. Get the one with the lowest price. The UM34C has one digit less and goes only to 4A (which is plenty enough for standard USB connectors and cables) while the UM25C has a digit more in resolution and goes up to 5A. The USB-C interface on both of these testers is very limited.
Heisenberg
Should I avoid the UM25C/UM34C?
Why? the testers are great. All this video was trying to say is don't use two inputs or two outputs at the same time. This is not something you would normally do but since these testers offer additional alternative connectors to save you hunting for the right converter cable or adaptor, the possibility exists that you can for example plug two inputs into a tester, with the predictable result that something can go wrong. To be fair, the tester probably survives, its more the devices on the other end that may be in trouble when you do this. Just stick with picking one input and one output and nothing will go wrong.
@@TheHWcave , I am trying to find a model that can test the capacity of batteries. Which one would you recommend?
@@jpvoodoo5522 They can all measure battery capacity. To test capacity when charging you need to reset their capacity counters, and then put them in between the battery and charger. To test discharging capacity you need to put them between battery and load. Which model is best depends on the type of USB connection you use (normal, micro or USB-C), but other than that all can do that. One note: If you measuring capacity of a USB power bank from the outside, remember that your are NOT measuring the batteries inside directly but through the DC-to-DC converter in the power bank. That completely messes up capacity figures because a Lithium battery capacity is rated at 3.7V but you are measuring at 5V (after DC-2-DC conversion). So its much better to measure ENERGY (watt hours) not amp hours, because watt hours measurements take the voltage step-up into account. All these 3 USB testers can measure energy as well as amp hours
What is your point? It is not lab testing equipment, just a tester.
You also can use a simple USB gadget:
www.ramser-elektro.at/lil-usb-tester-usb-schnittstelle-schnell-getestet/