SEQURE HT140 Voltage leak followup

[@TheBackyardChemist]

This is just a guess but I think you are seeing capacitive common mode coupling between the primary and secondary of the power supply. Tiny switch mode power supplies like USB bricks intentionally put a small capacitor between the GND of the low voltage output and the neutral of the incoming wall AC power. This sounds really stupid, but suppresses the radio frequency noise generated by the switching circuit, otherwise it screeches across the 100 kHz radio bands like a jammer. Putting a cap across the main transformer is the cheapest solution. Your lab power supply probably has a big iron transformer and a linear regulator which does not need a cap like this, but the windings of the transformer still form a parasitic capacitor because physics says metal + insulation + metal = capacitor. So you still get a much smaller but measurable voltage leak. The current is generally low, you can test this by putting a 10k resistor between the nasty tip and GND, you should find that the voltage on the tip is greatly reduced. The input impedance on most oscilloscopes is 1 megaohm, and 1-10 megaohm for multimeters. So this could still be an issue and damage components, but it is really easy to pick up voltages with a scope that only have microamps of maximum current. You need to test it under load to know that.

[@PeteSimpson]

Now that was a very interesting read, thank you...

[@Paul-xj1yi]

his power supply is in commutation i see after a fast google check thats why the leakage still manifest quite heavy, a power supply made with iron core transformer should be way better

[@xitywampas]

I was coming to say the same thing about cheap power bricks not being isolated and further testing is needed. I think you nailed it.

[@bornagain2641]

build a tiny test board with smaller more sensitive circuit, say a fuse tiny sensitive test bulbs and see if you can burn em out with the tool/tweezers

[@nikolaskallianiotis8622]

Tony, you can touch your mains live wire to the board and do no harm at all. The current needs a closed circuit to flow which in that case doesn't exist (doing soldering).

[@Petr01d]

A board itself is a huge chunk of copper which in combination with grounded electrical wires in your house, grounded rebars and pipes in the walls and the Earth itself makes a decent capacitor. Which in case of DC voltage would be almost completely harmless but we are talking AC here. And AC could flow through such capacitor. I don't know about US but where I live the neutral line is actually grounded at the power plant. That's why supplying the board with a (portion of) line voltage we are getting closed circuit here.

[@florianhofmann7553]

Solder iron GND is not connected to the board so the board should be safe as long as there is no voltage across both "arms". Measured the same way as you did, my Weller station has 15 VAC on the tip and I have soldered a lot of mosfets with that iron. Grounding the tip will get rid of the voltage in any case.

[@pjhb_microsoldering_portugal]

Hi Tony, please make a fallowup video with the comments information, this is an interesting issue, it happens the same with usb soldering irons. Thanks for sharing the info. Greetings from Portugal 🇵🇹

[@maItre_gonzo]

That's some AC coupling, and the USB power adapter looks quite bad (and that would be the case with most if not all of them, as they don't have a earth terminal usually). Your lab power supply is not that bad but is floating, you can try connecting the negative output to earth (middle point of the power supply is supposed to be earth, but better check to be sure). Check the tips body are connected to the dc-jack negative and/or USB shield (should be the case) and connect the other end to earth. That should solve this. I remember 20+ years ago we had a training on ESD (I used to work in a repair division for a big IT company), and I remember there were some discussions regarding the soldering equipments grounding terminal. Some said it's better to connect the grounding pin of the soldering station to mains earth, some other said you have to connect it to the board GND plane and some said it had to be connected to the ESD mat (but the ESD mat itself has to be connect to earth so...)... I can't remember what was the "right answer", but I think it' would be easier/safer to connect it to mains earth.

[@FrankCastle072]

Tony 50+ VL leak! No, it needs to have more testing with sacrificial cards. Its nice that the Manufacturer acknowledged the grounding issue, yet I would be more comfortable, in my opinion, performing tests on outdated GPU's that are perfect for lab testing purposes, before attempting a current gen GPU. -Deuces

[@wraith-kw5sh]

+1 definitely needs more testing also you could pull a fuse from a dead card to test it on to see if it will blow if it does then you have your answer

[@FrankCastle072]

@@wraith-kw5sh exactly! Well stated! -Deuces

[@timballam3675]

The issue is likely to be power supply related. This kills lots of SBCs running on non polarised usb wall warts.

[@logiclust]

i never thought to check the cheap-ass soldering gear i've picked up off of amazon... thanks, i shall have to do this

[@chryseus1331]

This generally isn't an issue in practice, all switching power supplies have some leakage, the current is usually quite low typically < 2mA, your board also needs to be connected to earth ground for this to have any effect, with ESD protection you have at least 1M ohm in series which assuming 100V would limit the current to 100uA, this is very unlikely to cause damage except with the most extremely sensitive components such as RF transistors.

[@inothome]

Measure it using the low impedance mode (Low-Z on Flukes) on the DMM if if has it. Basically goes from 10M Ohm resistance across the meter down to 2k (or less, I forget the actual number) and see what you measure. Or, use a 2k ohm resistor between the tip and a ground and measure the voltage drop across the resistor. That gets rid of any capacitive or inductive coupling, aka ghost voltage. If you still see voltage, then I would really worry. Or touch it with your finger before it heats up and see if the voltage drops to zero. Or, put the meter in current mode and see what current you're able to measure, if any. Still should be seeing what you are seeing to begin with, but it may be harmless.

[@satria4195]

The isolation from main(primary) to the output(secondary) on the power brick can be the factor(capacitance in between winding) AC can travel through Capacitance, and the Secondary output Ground is just Floating Ground

[@satria4195]

You can connect the tweezer body to the ground with a resistor, but that will added mess with the cabling(good USB cable), or you can modify the power brick output port body to connect to the ground also with resistor

[@klorslug]

@@satria4195good advice for a workaround, problem for noobs like me, I shouldn’t have to try and fix a new tool for something the manufacturer should have done in the first place.

[@satria4195]

@@klorslug I would measure the Voltage Leakage Out from the Power Brick/Supply or the Cable Connected to First to ensure which the culprit

[@darrenday1467]

That is known as 'Touch current' and probably comes from the plug-in charger (earth leakage), very low current (

[@andrzejmialkowski4077]

Leak of half of input voltage via filtering capacitors is normal for class II power supplies (fully isolated ;). There are always two capacitors between L and N creating capacitive voltage divider to input ground of the supply. What you likely want is to ground output of the power supply.

[@realmamal]

For safety, you have to isolate the card and then use the soldering tweezers. It doesn't have a voltage difference between legs.

[@kiwichess]

I remember that early versions of T12 soldering stations like KSGER and Quicko (then T245 AiXun too) had this tip grounding issue which IMO (can be wrong) was resolved in later versions. But there was like 3v or so, not 50v for sure.

[@the-d-r]

The Voltage is irrelevant. To damage something on a board, you need current flowing through your circuit. You can do the test again, but this time please ground the tweezers but with a high value resistor like 1-2 or 5 MOhm. And my guess is, that the voltage leak will just disappear. On the other hand, you need a circuit, so energy can flow. Where is your circuit, when you are working on a GPU PCB on your bench? Not connected to anything?

[@orangetimes2799]

I just checked my Pinecil v2.0 and it has the same problem. The leakage current is about 40 microAmps

[@darek7524]

Class II devices can struggle with electromagnetic compatibility issues (EMC). To resolve this, the earth connection is used as a Functional Earth (FE) in my opinion solder tips should be grounded

[@NaN_INF]

That 50 ACV to ground will not create a current flowing through the board unless the board you are working on is also connected to ground.

[@northwestrepair]

yes but unfortunately that is often the case.

[@TubeSkaterRudy]

Yes you should connect a pcb to ground including yourself. That's standard procedure for handling cmos chips that are highly sensitive to static discharges.

[@brnmcc01]

@@northwestrepair Do you have a meter with a microamp current function? What you need to do to determine if this is just 'phantom' power (like a surface charge), is measure how much current actually flows from the soldering tips to the ground. You oscilloscope and digital multimeter should have at least 1 megohm or higher input impedance. Otherwise it wouldn't be capable of accurately measuring very tiny amounts of power without adding voltage drop to the circuit. If you get only 1 microamp or less of leakage current from the soldering tip to a good ground, then it's probably not enough to do anything. Things that run on very low voltage like a core, have very low internal resistance like you measured some before with a milliohm meter, and they can handle a couple of amps. The thing I would be worried about is the initial current spike if you touch those probes with a surface charge of 52 volts to something sensitive. Sure, once you touch the component with some liquid solder, it'll make a good connection and drop the voltage to zero. But that initial spike of 52 volts, potentially over and over as you try to move a small capacitor or fuse into place would potentially be pretty sketchy. I guess a possible way to check that would be to measure the capacitance between the soldering tip and ground with no power supply connected to the soldering station. If you can measure anything more than a few pico farads, then I wouldn't use it. The soldering station could have some capacitance, and you can do the math from there. For example a 1 pico farad capacitor charged to 2000 volts and you touch both leads with your fingers, you would barely even get a tiny static spark. Like a barely noticeable static shock. A painful static shock from dragging your shoes on a dry carpet and touching a doorknob can be 50 kilovolts or even 100 kilovolts. On the other hand, if you charge a large microwave oven capacitor of a dozen or so microfarads to 2000 volts, and you touch it, you would die instantly. Or would blow up a GPU permanently., like blow a chunk out of it. It's all about how many joules of energy is stored in those soldering station tips at the moment it touches the circuit you're trying to fix. It's not the voltage or the amps that kills a person or a component. It's the total amount of energy. Static shock = extremely high voltage, but nearly 0 amps.

[@--_DJ_--]

@@northwestrepair In what case, is that the case? I'm not doubting you, just curious. Usually we see the board sitting on the bench when you are repairing them and there doesn't seem to be anything that would provide a ground unless the mat you work on is doing that.

[@brnmcc01]

@@TubeSkaterRudy Especially in the wintertime. Here in the midwest it's humid enough in the summer static isn't really an issue. But once it hits 0F or -20C outside and gets dry, it's hard to even do normal stuff in the house without getting constantly shocked. Walking around on carpet with socks on is a shocking experience on a cold winter day... My rule of thumb is, if it hurts touching a doorknob, then it'll blow up a chip no problem.

[@paulvanderwielen8173]

thanks for your info, In case of using the lab power supply and connecting the negative lead to earth (white terminal to black terminal) would you than still measure a voltage on the tips to ground ??

[@stoptheirlies]

Hi Tony, I don't see it matters, there is no return when you are using the soldering iron so it's just a floating voltage and will not harm anything, have a look how much A/C comes out the end of your finger on the scope

[@computerthrills]

If there is no voltage potential between the two soldering tips and the board is not grounded in any way. Which I don't see why it would be during soldering. I wouldn't think there would be a problem. You are providing a pathway to ground with your testing methods. If there is voltage between the tips. That would definitely be a problem. But it is just my humble opinion. If I need to be enlightened. Please do so. Thank you.

[@TheVaryingVariable]

Big clive tore down a cheap bedazzler iron in a recent video and saw that the only insulation they used between the iron tip and heating element contacts was kapton. Not sure if this is a power supply isolation issue or just cheap design to have this severe coupling.

[@anomicxtreme]

Wow..... Try using a thermal camera while using it on the dead board and see if anything lights up with heat.

[@genomeyganomey6647]

I mean you could use a dedicated USB c power isolator so that you don't have to worry about any electrical charge flowing into the electronics. I'm not sure if they handle USB-PD, but for the DC barrel jacks, you can definitely get isolated power supplies for them (I personally use ones that look like boost converters) [Also fyi Computer Engineering grad student if that means anything]

[@northwestrepair]

I tried that, very similar result.

[@spectator-w9m]

@@northwestrepair Then I would test with a battery such as an 18v tool battery. If the same result, you have a noise problem with some of your other equipment.

[@catharperfect7036]

That will also stop the Chi-Comms from hacking the tweezers with glitching attacks. Well noted.

[@QARepair]

Happy New Year! Best Wishes to Everyone !

[@marcellipovsky8222]

If you are concerned, get a big powerbank and use that one to power the tweezers.

[@silverstone7778]

That's no good. But on one Hand, that's the side-effect of having a Class II Power Supply: it's NOT connected to Earth, you only have 2 Leads (N, L), and the Way they solve the EMC Issue is through some EMC Capacitors between Primary (230VAC, 50Hz) and Secondary (whatever V, DC) and some discharge resistors across. Now, especially if it's NOT turned on (load Impedance = Infinite in an Ideal World), then you got a nice Voltage Divider going on depending on the Transformer, Resistance and Capacitance Value. The real Question would be what's the Voltage when it's turned ON. Because then the Load Impedance should get pretty Low, thus less Voltage will be transmitted "across" the Transformer due to the Discharge Resistor / Load Resistor Ratio, essentially tending towards 0). The Question about Voltage is always: between WHICH two points do you Measure or Apply your Voltage ? If your PCB has a low-impedance Discharge Resistor or something to Earth (and you have your PCB earthed during Measurement/Rework, such as might happen on your Heating Plate - not sure that is Earthed, it probably should be), then it might cause damage. If your PCB is floating, then ... dependents on the Parasitic Coupling Capacitance to your Table, Floor, Earth, etc, not much might happen. The main Question in my View is: what's the voltage between the 2 Tweezers, as that's what you're more likely to touch 2 pins of the same Integrated Circuit. Depending how the resistive Heater is done, if it's a ceramic Heater that's then conducted to these iron "Rods", there really shouldn't be any Voltage at all. But of course if they use the Tweezers themselves as heaters (assuming there are 2 "wires" in each Tweezer, e.g. "supply" and "return", or "inside" and "outside" - you definitively do NOT want to close the Electric Heating Circuit through the PCB between Tweezer 1 and Tweezer 2 ...), then you might also have a big Voltage across your Tweezers (Voltage between Tweezer 1 and Tweezer 2). But again, it's the Differential Voltage at their respective Tips that matters in most Cases. Common Mode Voltage vs Differential Mode Voltage essentially.

[@Hossimo]

That doesn't seem good but how much current is behind it.

[@rudybikerpunk]

Mostly used pace thermal tweezers but never checked those for voltage leaks.

[@stargalacticfederation]

I was just about to purchase one, I'm glad I come across this video, it would have been a disaster if I purchased it, I used to be electronic engineer, my advice to you is ,to send it back and let them know the problem because it's wrong, because you can cause damage to the IC chips., so thank you for sharing the problem, great work.

[@dejanpetkovski8761]

The PSU is the problem not a tweezers and all PSU nova days have same problem try measure you phone charger is the same and don`t worry you will not die or damage your chip.

[@stargalacticfederation]

@@dejanpetkovski8761 I Disagree With You, 3 Volt DC Is Normal, But However 52 Volt AC Is Not Normal.

[@chryseus1331]

​@@stargalacticfederation Completely wrong, take any switching power supply and measure it yourself, you'll find roughly 1/2 the line voltage to earth, this is required to reduce EMI.

[@dejanpetkovski8761]

@@stargalacticfederation Like i say all is up to PSU not the tweezers.

[@citizensteve6713]

I would like to think that it would be only applying the 50ish volts to only the components you’d be removing. Is it only one tweezer leg that leaks, or what about when both are together?

[@custume]

well, 50 volts is a "tad" hight, like really high, but unless you have the PCIE or the power cables connected to the board there is no way for the voltage to go any place, the amps on that if is on the mlv range that good but even low mlv with 50 volts (DC or AC) is a bit hight (especially for the core), the rest will survive that. Also been a tweezers if you get AC between the tweezers points is bad, like really bad, because it can close the circuit, sure it will go for the sorted route but even that if you have no filter caps it can go "other places"

[@kylesaver167]

the thing seems like its not grounded, that's same insane voltage leak. Is it possible it's the PSU? what happens if its just a normal High Quality DC power brick that is grounded?

[@petehort7940]

Does the PCB need to be grounded for the voltage to leak in?.

[@iphonegoes1250]

YOU SHOULD TRY MEASURE HOW MUCH AMP THIS THING SUPPLY TO.. NEVER HAD A PROBLEM WITH MY OLD AC SOLDER IRON.. AND IT INJECTS AC INTO THE DC BOARDS ..🥰🥰🥰🥰

[@PhoneRepairRO]

Is the electric potential or something like that (i don't know the name in english) between 2 power supplies - the one that you power the SEQURE HT140 and the one that is inside the SEQURE HT140. Try to use a linear power supply (with transformer and rectifier inside) not a switching power supply, you will see the difference.

[@ford1546]

Could have been interesting to get an answer from those who make and sell this and hear what they say about the problem. can you try it

[@teddp]

Great stuff, a pair of soldering tweezers that can both solder your chips and fry them at the same time 👍😂

[@weelesway4367]

C😢can I get help how to ship or send card

[@teddp]

Press on the channel press about​@@weelesway4367

[@hamzasaidi28]

Of course, use is sometimes harmful, for example, circuits that contain low voltage capacitors, especially if there is a pre-charged voltage, or in voltage boosting circuits, feedback, or oscillating insulators. This is from my humble point of view. You know that caution is required, despite the device's distinction. The manufacturer must fix this simple leak to the metal cover, which can be insulated. Why doesn't the company add a magnetic sensor for automatic on and off.Thank you, Bro, for the professional content.

[@LifeChanger_._]

Shouldn't all soldering tips be grounded? I have never measured mine, I'm going to have to know, I have Aixun T420D, 2 of them....

[@neofantasy418]

you need an isolated power supply

[@jeffcole5708]

My soldering station is giving out a lot bigger ac voltage, found out that the Aixun soldering station gives out much more.

[@RickDkkrd]

Thanks for the heads up

[@GameBacardi]

Could there be interfere what show AC so much ? Then current is very low.... ?

[@fu1r4]

When you charge your laptop by USB-C you can feel how it tickles in your fingertips when you pull them gently over the lid ... And you still haven't removed the screen protection 🤔

[@FSerpentxnitro]

is it possible to ground the out side of the soldering pins or wil that short the tweeters?

[@timballam3675]

Switch mode PSUs have caps that cause this. The PSU is probably "floating" and if using a switch mode PSU could suffer from the same problem. Have you tried strapping the negative of the PSU to ground?

[@youcainthandlethetruth]

Are you located in usa?

[@Guraba_AzE]

da fließt 22 μA je mehr Spannung bei HT140 angelegt wird desto mehr Spikes. Ich habe zwischen 3v und 22V gemessen bei 27v DCIN.

[@jonnygudman1815]

The soldering tips or soldering stations should always be connected to the ground of the work material, for ESD safety reasons. 12V at the tips is probably an insulation fault in the heater? Fix the fault and, ideally, add a socket for grounding both soldering tips with a resistor or inform the manufacturer.

[@klorslug]

That’s so much more voltage leak than I was expecting. I’d be worried to use it on something sensitive. Maybe an internal grounding issue?

[@SergeyKucheryavy]

@@klorslug there is no ground there it’s not connected at all

[@katlegomogwera6834]

I don't you need to worry if soldering cards not connected to mains.

[@dg_cato2644]

Do what you always do and mod it to your specifications 👍 lol as is I probably wouldn't trust it either

[@aknet99]

I think the 52 volts it's because you have a floating earth ground respect to the AC/DC PSU adapter. You should try to tie the USB ground to earth. The case with the DC Lab PSU try to connect the negative to earth binding post.

[@jameshackett9992]

use a lithium USB power pack. , or connect the USB gnd to gnd for esd protection. Have a nice linear toroidal bench PSU, with seperate earth on the neutral,

[@SergeyKucheryavy]

@@jameshackett9992 power bank will helps, but for what? Author doesn’t use grounding at all, but tweezers doesn’t galvanically isolated and manufacturer should care about that. At all it’s a creepy Chinese shit

[@Professorke]

All my measuring and soldering equipment is separated from the mains with an isolation transformer, which is the only way I find safe.

[@Alan_Skywalker]

Take it apart and wire the screws to the usb port?

[@northwestrepair]

They are already wired. I checked.

[@AntonBabiy]

Any ungrounded switch mode power supply will have this behavior. Take any 2 prong usb brick and measure it's output to ground and you'll get super low current high voltage. That being said, it's completely unacceptable for a soldering iron to act like this and the gnd on the adapter needs to be connected to earth ground

[@SergeyKucheryavy]

It's a good way to power up your almost fixed graphics card.

[@5nowChain5]

Or OC it 😮😢😢😢😢

[@JohnWilliams-gy5yc]

1060: God! No. Not before Trump pardon me in early January.

[@huguess74]

If the card and the man are not connected to the ground the risk is low??!! A professional station costs 1500 to 2500€ if anyone manages to manufacture similar equipment for 150€ there will be closures of the best factories. Thanks for your great videos and have a great Christmas!

[@slkslk9324]

why don t you make video hon how to ground that v by dissambeling the twizer and grounding it you can modify it and make no leakage just like your profersionnel TB3 station

[@alexualexul]

I might have destroyed some bluetooth headphones with a soldering iron that does that...

[@jasonkaiser1179]

4 diodes need to be put somewhere.

[@teknologyguy5638]

Seems like an engineer needs to shed some light on this one... but for me, it simply means I'm glad I didn't buy one of these yet.

[@GameBacardi]

God dam... scrazy shit :(

[@MrXepi]

Hey man :) Quick question my tuf motherboard have started showing a red light when I wake up in the morning and the screen is black. Gotta restart pc to make it work again. Motherboard is Asus TUF B650-PLUS WIFI, graphics card is XFX MERC 310 7900XTX and a 850 PSU.

[@MasterJediSean]

Turn off Hibernation mode in Power settings.

[@MrXepi]

@MasterJediSean Hehehe is that it? xD It may be I will try thanks :)

[@MrXepi]

@@MasterJediSean "Hibernate The hiberfile type does not support hibernation." Its not that damn it only happens when pc have been on and not used for a long time so good suggestion.

[@yanleb1]

Is it UL certified for USA or CSA approved for Canada? If no then you have your answer. 80% of the electronic or electrical items sold on Amazon is not certified. All Chinese junk sold by unethical sellers.

[@iphonegoes1250]

MY SOLDER IRON CAN LIGHT UP A 3V LED..🥰🥰🥰🥰🥰🥰🥰

[@northwestrepair]

lol nice

[@weelesway4367]

Help me I need help with my gtx 1070 ti can some one help me I need to ship my gpu

[@Uncle-Duncan-Shack]

Does not take much current to kill Cmos devices. That is why static is such a killer of electronic components, does not take much. A earthed iron is essential when working on electronics. I would only use stuff that can be securely earthed.

[@catharperfect7036]

I used these tweezers to remove a couple of BIOS chips ready for re-programming. Do you think I nuked them?

[@Uncle-Duncan-Shack]

@@catharperfect7036 These days the ic's have protection diodes to the supply rails, so probably not. But considering the earthing of the iron is maybe not a bad idea.

[@thealmightysnoood]

Use the soldering tweezers. Drama is fun. I'm being helpful.

[@DevilbyMoonlight]

When something seems too good to be true.. it usually is... I suspect a really good PSU may reduce this issue, but how much.. who knows!

[@batman4e]

Even 1 Volt is too much!

[@stevencharette7918]

does it really matter though as long as the device works as intended i mean its not going to blow up in ur hands or melt itself but good follow up for the nerds out there who need the math numbers for every little thing in life

[@MrDvneil]

It does matter because injecting 20 volts dc to a gpu core would kill it

[@brnmcc01]

@@MrDvneil It depends on the output impedance of that 20 volt source. If the output impedance is in the megohms, and a GPU core is only a few hundred milliohms, basically a dead short, then nothing will happen because the amount of current that will flow thru the total circuit (1 megohm + 400 milliohms core resistance) with a 20 volt supply would be following Ohms law 2/100,000ths of an amp. Practically too low to measure. Small devices like an Apple watch or even a quartz watch movement that run on 20 microamps or even less would probably be toast though. On the other hand, if you apply 12 volts from a 1000 watt power supply to a GPU core, then the resulting short circuit current would be assuming 450 milliohms core resistance, plus 144 milliohms power supply internal resistance, then the total current flow is a little over 20 amps, which is more than enough to blow up a core.