I watched this entire video and couldn't believe that an hour had passed when it was over. I guess I've progressed beyond "complete beginner" because I was hoping to see the board powered up and what would happen if a scope was attached to the TX pin or a pulse generator was attached to the RX pin. I don't know a lot about cars, so I also wondered why a car with a battery even needs a bridge rectifier to convert AC to DC. I looked up how alternators work and figured that out and learned about what inverters do in the process. This was definitely the right information for me at the right time.
These videos are among my fav where we mess with different sorts of circuits. As more of a hobbyist troubleshooter these days, I probably couldn't resist taking the next steps of firing up the oscope and LA and powering the sucker up to note behavior. I can't help myself, but for someone where time is money, that is a unprofitable approach in this case. Well done.
That is the transponder coil of a category 2 thatcham approved immobiliser. The black ring picks up the chip in the car key and relays the stored immo data/code via the coil and module to the ecu or dash clocks to authorise or deny an start attempt. Acc is accessory position ie dash lights on but not cranking to start. You can usually read the immo chip but as mentioned by others here, you’ll likely not be able to edit the bin as they use incremental registers to prevent you editing the first two lines containing the immo status
Sometimes the research hours we spend goes overlooked especially if it puts a smile on the customers face. Sometimes that smiling face gets us further along as well. I havent finished watching this video yet but i bet we figure it out.
Can I suggest you get yourself a ball of "bluetack" and use it to stabilize your board/assembly whilst attempting the surface mount soldering. Just stick the board/assembly down on top of the Bluetack and it should stay in place while you prod and poke the components. Great videos, as a novice I am learning much from them.
Hope you're having a good day I have found that by applying white thermal paste onto and wiping it off ic's and transistors you then can read the numbers very well, thanks for all your videos.
Nothing wrong with it from the start, the bloke nicked the car !! Good effort and I felt your pain as the probes skidded off the conformal coating, perhaps your next Ali order should include a small bench vice !...cheers.
Heh yeah, most obvious application for 'electronics connected to the ignition switch' is an anti-theft device and the most obvious reason for it being 'broken' is that someone's stolen the car or lost their key and doesn't want to pay the manufacturer to sort it. Take it around to your local electronics expert to see what he can do.
Many standard diodes come in chips of multiple diodes. Sometimes these are connected and sometimes it's just convient packing of separate diodes. The same is tru for chip resistors as well. All the time you were calling the diode package a bridge rectifier I screaming "Look at the schematic!" Not that I haven't done the same thing myself... I enjoy your videos! Keep making them!
Richard, I'd like to add few pence from myself. 1. Why overcomplicate things? What I mean is it took me several watch attempts to reach 33 minutes of the recording, to start to see shorts :D. How this will attract new people to start fixing electronics? 2. I'd make it more simple. But... . I've started fixing in the '90s, I've forgotten a lot and 3 times I've quitted fixing them. But, was working for 3.5 years in the computer shop and microsoldering since 2021. So, know a bit about it ;) you can say. Run as well a five-star rated with over 110 reviews electronics repair shop to make it more clear with several people helping me and over 100 active jobs. 3. How I would have done it is. First, do the visual inspection. If no findings step no. 2, check for shorts. If you don't know how to do it, start learning which components are capable of shorting circuit. If you can't find any shorts, supply voltage. If you have to apply 230V, do it via bulb. If bulb is lighting up, you've missed something. If not, no short. If you can't find a short, that means that something is not connecting, burned, or a firmware fault on some IC. And explain how to check it. And, how to replace it, or redesign it - even using Arduino, ESP32 ;), etc.
It's a bit inconsequential to the diagnosis, but I think you misread the voltage on the electrolytic cap as 6v when it's 16v, most 6v caps are 6.3v.. it would also make sense that an automotive system would run on 12V
Hehehe that dual diode 4 pin device is shown on the data sheet typical configuration you found...I was screaming 😅 Love your channel and your instructing methods of fault finding without schematics 👍
ACC= accessories. With engine off. You can listen to your radio, charge ph, ect. when you turn your key to ACC. You wont have battery power going through your alternator saving it from burning up because it's not turning the fans inside the alternator. With the key in ACC It also keeps your fuel pump from running 👍
@davidcross30 Sometimes you don't have access the vehicle or whatever a PCB comes from (industrial crane, fork lift truck, sausage making machine, F1 car engine cam shaft measurement rig, control pendant - these are just a few real life examples of things I repaired when working for an industrial electronics repair company). Sure in a perfect world you would have access to the item the PCB came from but in the real world that often is not the case. So then you have to use other methods and that is what I am trying to show here - a methodical way to approach a PCB repair without knowing what it does. Sometimes this method will allow you to fix stuff and sometimes it wont but sometimes this is the best approach available. Your comments and those who 'liked' it suggest it is not possible to repair stuff this way. I differ in opinion and think it is surprising what actually is possible.
@@LearnElectronicsRepair Absolutely Rich you certainly can look at what is wrong on the board but in this instance with important pieces of this system missing it is almost impossible to ascertain which part of the overall system is at fault - there are inputs to this board and it provides outputs to other boards/systems. I dare say (as an automotive engineer) that the fault is elsewhere and I would always start fault finding on the whole system. Like you say If you can't do that, like in this case, you can scratch around to see if the components on the board are okay but other than that there isn't much else that can be done. I MUST say however Rich. I bloody love your videos and I'm learning much more than ever before. Keep up the great work my man. And I did indeed like the video too; I always do.
Likely powered by automotive 5V reference (supply) voltage from the ECU.. Tx/Rx likely goes to the CAN bus. Having the scan data from the vehicle, specifically Security/anti-theft/key transponder (& is the transponder in the key any good?), via a scan tool from the customer would have helped. PS, check out and get an RTL-SDR dongle, as it is cheap and effective receiving a very broadband of RF signals .. in this case, finding out if this device is in fact transmitting.
I recommend the books "practical electronics for inventors" and "diagnose and fix everything electronic" And for UA-cam channels: great Scott, Northridge fix, Andrew speiss
my suggestion would be that the shop check with oscilloscope if the ecu pins are getting the signals and from there you can conclude something like broken key or the chip here is faulty, because as you showed the antenna is working, which often is the problem with this systems, but maybe not this time
This might be a job for the Fnirsi portable oscilloscope. You could connect it to the antenna and see if there are any signals present as this looks to be a transmitter only device. The question also is if this device is receiving the signals to transmit from the controller. P.S.> Richard I hope you fixed up a bit those solder contacts, because while you were poking and poking and poking them,you almost destroyed some 😁😁😁
I wanted to power the PCB up and see if we could see an oscillation on the inductor - I even looked at the datasheet to see what logic levels we may need to put on the inputs to get it to do something. Unfortunately the owner wanted it back the next morning so I didn't get chance so apart from explaining how we could test that chip I wasn't able to try it. I did give him a quote to continue the job so hopefully he will bring it back in
That type of Immobilizer works by using the induction loop in the ignition to send a radio wave (similar to how wireless charging works)this causes the key to broadcast a frequency that is compared to the reference signal stored in memory.
Richard, you spent quite same time trying to figure out what the D1 device with 4 legs was, when it was clear from the diagram that is 2 diodes! and 2pins are shorted together as per the diagram
The data sheet I found describes the ic as a transformer package that’s control by external Hall effect signal. General question, with the components of off the pcb, Can a component tester identify smd transistors, diodes, etc??
Dear Richard, first im grateful for your effort to teach us. Can you please make a video on How to analyze a laptop battery li-ions how to reset BQchip charging cycle count. Identify and replace dead 🔋. Thanks
That cap is 16 volts not 6, most vehicles have a 12 volt DC electrical system omitting big trucks, planes, locomotives, busses and heavy equipment. Anyways the device looks like an RFID reader that reads the chips in new vehicle keys. The physical key unlocks the steering and engages the contacts for the starter but the chip in the key authorizes the BCM (Body control module )computer to enable the vehicles start and run electrical system that will supply power to the starter, fuel pump, ECM, instrument cluster, stereo, etc.
Yup one like that in my van but the PCB is like 6x that in area with old through hole parts. Mine reads the transponder chip in the key, it's a glass bead type line in a dog/cat under skin chip/tag. If the code read matches it's memory, then a secret handshake is sent to the engine ECU allowing the engine to run until the next power cycle. It's an ac signal to the coil and the reflected waveform is monitored, three chip in the key has a coil that receives the waveform and rectifies that as a power source to transmit it's code back with. Similar protocol to NFC but afaik the code in my key is fixed ID number and can't be written
Yeah… i have one guy that keeps on bringing in single PCB’s from larger systems. He diagnosed that PCB to be faulty. No other info. With lots of reverse engineering, I normally have to tell him to bring in another PCB, on which the fault actually is. I guess that is a way to fix stuff that is too large or difficult to bring in, lol… but it is still easieer than taking all my equipment to a premise and look for faults whilst it is -40C outside. The upiside is that one learn so much from reverse-engineering a PCB, figuring out how to test it, and derive where the fault actually is. Biggest problem is always finding data sheets for those weird industrial chips….
if chip has problem, is possible to check with multimeter on diode mode? i mean : red on ground of chip and see with the black on each pin if there is a short. Thanks a lot for your videos, keep up the good work !
They came as part of a large probe kit from Kaiweets called KET05 They really are excellent, and I have used a lot of meter probes over the decades so I do know good ones when I find them www.aliexpress.com/item/1005003727037642.html?af=ler2022
Yeah I could have done that also. The capacitor is directly across what I worked out to be the DC input so it probably would not cause a problem even if it wasn't there, but as I don't know where the 5V regulator is, maybe it does need the electrolytic to be present in order regulate - so yours is a good suggestion
@@LearnElectronicsRepair I’m still learning so, please bear with me: Do you mean to say that, electrolytic capacitors are sometimes used instead of voltage regulators? Is that really possible? Please clarify. I want to learn. Thank you kindly, sir.
Richard, I don't know if you mentioned this before, but it might help people to know that the collector always reads a bit higher than the emitter. Knowing this fact can help people know which is which and also if the transistor is faulty, because the two numbers are always very close readings. For instance, 0.768 on the collector and 0.764 on the emitter would be a typical gap between them. It seems to be something many people aren't aware of. You said that the emitter sometimes reads lower, but doesn't it always read lower? Maybe I didn't test enough, but I tested a lot an the emitter was always a bit lower. I'm curious to know if you ever found the emitter to be higher.
Hello, i have a electronic board of kids car damaged one component have burned but i dont know whats name of it or what numer serial have, pleas help me
T1 and t2 look like ghey could be a half bridge to drive the coil. Very hard to fault find this as you need to be able to tell it to turn on and read the key. So you need the data format for the coms bus, and if chip has an issue then your probably need to reprogram the ecu. These are mosty a no win
Big storage capacitor is 16V not 6V. No 1 is barely seen at the edge. I think the problem is not in the Cct. Owner of the car may have used a mechanically duplicate key instead of using the original smart key to start.🤭
@@LearnElectronicsRepairYou are correct!, Sorry if I've being rude to you, b'cos my English is so poor. I'm 52 now and I found you are a very experianced helpful technician from all arround the world. what do you think of my 2nd guess?
@@BjornV78 i still dont see how its 12 volt line when the chip is working max up to 5.5 volts? Do you see some power supply or something that will drop the voltage to 5? because i dont see it. It can be that they used the capacitors they have in stock, as someone said the 16volts are used almost anywhere, and using higher voltage capacitor than the rail is using wont hurt anything
That little four-legged device was a bridge, it just had the two AC corners strapped together, so two diodes in parallel “up” and two diodes in parallel from ground up to the signal line. Generally I wont take on this type of job….the reason? Because this is not the WHOLE device, but rather just a part of it….and the whole…I.e. the whole rest of the vehicle works as a unit and..as the bloke who owned it said, he was not even sure the real fault was not somewhere else in the other part of the circuit you did not get to see. There is another way to look at it though…if you have the gear…this is automotive, nowdays a lot of automotive seems to yse the CAN bus standard….I think another place this is now used a lot is in disco/night club/theatre lighting control. So IF you have test gear that will generate and recognize CAN bus packets….and a lot of contemporary oscilloscopes do have various digital protocols that can be selected in triggering options…and if you had a signal generator that did CAN bus too…then you could concievably do something meaningful with it…but without such gear I feel I,d be wasting my time. This is what makes this sort of hybrid comms or even servo control stuff so unrewarding…take an electronic washing machine or E-bike or some other such part electronic, part mechanical, part hydraulic circuit/system where opto interupters or hall sensors and motors connect the electronic bits to the other thechnologies…these have to be worked on as a system, just looking at the electronic bits in isolation to the rest of it is generally pretty unproductive or inconclusive…as this was. I got landed with a boat controller the other day, it had dozens of inputs, all protected with varistors, transzorbs and inductors, it had dozens of outputs too, from bug mosfet half bridges through filter networks, some PWM proportional, some just on-off digital. Took me a good hour and a half to get the lid off and dig down through the compliant goo to the board. There was a big micro, with Rom And Ram….I identified the power input and hooked it up to the bench supply, I found the crystal of the master clock…it eas running so the micro was working…And I would have done the same there with yourgadget, Put 5v across that electro and the CRO probe straight onto that ceramic resonator…if is wad oscillating i would have taken a quick look at the data out and waved an expendable RFID card over the “Antenna” …um, coil…if the trace changed at all on the scope I’D have deemed it a “goer” and told the bloke to look elsewhere…back to the boat controller…I eventually found a Lithium Primary cell that obviously held up some volatile contents in one of the memories…it eas dead flat…so I assumed the firmware was gone and went no further without gear that could specifically communicate with it. I susprcted the bloke who owned it simply scrapped it and forked out for a whole new unit when the onternal battery went flat. It wax biught to me by a mutual friend but I was given no fault discription or even any pressure to repair as he had already replaced it and just thoufgt I might learn something from it. I suppose I could put a new primary cell in it and take it back to him to try, but that wiuld be all. I imagine such a thing failing whilst you were far out off the continental shelf….I’d definitely want a far more low tech and less fault prone system to get me home. This is why I generally just wirk on complete electronic only sysyems that are self contained and I can get up onto the bench!
Heya yes very educational even wen you don't know the working of the part you still can do some measurements of the componments on the pcb to see if there would be a fault componment have not tought about that route thanks
Replacing the chip probably won't help, you also have to program the original RFID key code in the vehicle computer, if it is corrupted. It is very seldom these RFID readers become defective. I make and sell a lot of RFID lock system, and it is very rarely I see a defect.
I would agree with that ans suggested to so much in the video. The datasheet for this chip proves it is purely an interface between the key code generator (wherever that is on the vehicle, in the ECU?) and the antenna that communicates with the key fob. Or at lease that is how I read the datasheet and typical app. As you have more specific knowledge of this system, could you elaborate on why I can't replace that chip with another one? As an aside I don't actually believe the chip is faulty, I basically just proved that nothing else on the PCB is faulty, therefore the chip is the only thing left. Of an the crystal resonator. As I mentioned at the end the customer picked it back up before I could complete the investigation how I would have liked to. Hopefully he will bring it back
@@LearnElectronicsRepair Unfortunately I don't know much about car computers and where the code is stored. I don't do cars. But the reason I don't think the chip is faulty is because if it is you would expect that the car bus/computer would return some kind of error code if it can't communicate with the immobilizer reader. This sounds more like a job for an OBD tester considering how complicated a modern car operating system actually is. I think this fault could be everywhere, and I don't believe he has sufficient evidence to say that the reader circuit is faulty.
The circuit you have is actually not just a reader, it does also have the ability to *write* to the key. Because the EU demands that all cars have the ability to write/prepare a new key blank. So your circuit is actually a part of a more advanced system making your circuit a more or less dumb passive circuit that just facilitates the communication with the key rfid.
I would recommend to buy 1) a board holder, and 2) a solder station with a small pointy tip. Your tip is much too big. For SMB even totally unusable. The current one looks as those old ones without temperature control. If it has none you should get definitively a solder station with temp control.
18:10 Replacing a IC that is part of a car electronics system is not an option anymore these days, almost every circuit in a car is connected to the ECU (main computer) and use CANbus fault diagnostics and has a serial number attached to it. The guy that ask you to look at this part, has propably got a high repair quote from the car dealer, and didn't want to pay for that. When such a part like this RFID ignition slot is replaced at the car dealer, the ECU has to be reprogram to accept the new part, and also only the car dealer knows the exact frequency that match the key fob of the customer. Otherwise everybody could ordered this part online, and could start a stolen car.
that's look like from old car, and many times you can just replace the part, it don't look like CAN communication and also this board and antenna are just rf transmitting and receiving, they don't do anything to the signal
every'one' NOT every'body ' Ask yourself this simple question How many of YOU are there in existence in this world ? Learn that Legal and proper grammatical Legal English a BODY refers to a DEAD entity You will find them buried in the cemetery. Go and visit and while you are there - pay attention to HOW the name of the CORPSES is written. HOW something is written is CRITICAL - but the ZOMBIES in this world do not notice the detail as they are semi-conscious. One has to learn Law at a high level and Latin to be proficient and competent in the English language. Common Street English is Peasant level English - That is what is taught in CORPORATE GOVERNMENT indoctrination institutions known as School Good luck and good bye Learn the above lesson and teach it to the ignorant masses
whilst work of this type (part of a system/not self contained module - especially of unknown functionality) can be potentially useful brain teaser exercise, its otherwise rarely productive and most definitely not economically viable. simple circuit with only one marked, not-programmable chip that has available datasheet - and still got pretty much nowhere
oh pleeeze, can you stop the board skating all over your bench. FIX it in place. And use probes correctly, aim down from the top, not very obliquely from the side so that you are skidding off the contact (solder) all the time.
when you poke the solder pads.. i cringe so bad.. as it drags across the traces and leaves a crater in its wake... scraping the whole board up.. ugghhhhh... cringe, cringe, cringe.. but i love ur videos.. please keep up the good work..
How do you suggest I get a connection through the coating on this PCB without poking holes in it, or make some required tests without getting a connection. I'm all for improving my technigue as regular viewers will know.
@@LearnElectronicsRepair I am a regular viewer.. subscribed & like every video.. it was not a put down.. i know there was a coating.. just under microscope.. u can really see what the probes do... that's all i am saying.. i love your videos, please keep up the good work.. I am a beginner in electronics.. (hardware).. (I've been a programmer for 27 years in many languages (software)).. I am trying to learn everything i can.. the basic components & how to test them.. can you do a beginners run through of common components, how to test them with multimeter.. & find faults & what mode used.. i know u have a few vids like that.. but they were drawn out & i was still confused at the end.. something more straight to the point, focused.. using your experience & pitfalls, & how to know if a component is bad in-circuit..
I didn't get your repair technique that takes 1 hour and ends up not knowing the reason behind the fault. Sorry, i appreciate your channel but looks like your video's title is a clickbait to me. Also testing unknown components onboard is not the right technique.
I agree. I frequently watch Northridge fix and coming from there to watching Richard fumble around with a tiny board and no pcb holder was just painful to watch. The order at which he was checking components was also questionable. Checking for low resistance on resistors but not on the electrolytic cap. No ESR measurement on that either
@@zeddpilsner4 lol comparing Northidge fix to Richards is like comparing Ferrari to fiat in favor of Richard. Alex is just good at soldering and he is very bad at troubleshooting, and on the other hand is Richard who has very good experience and can fix most of the stuff with his methodical approaches. Alex often cant repair anything that he never worked on :)
@@ДимитърАндонов-ъ7е well i have to agree that Northidge is awful. Search for "Electronics Repair School", he's doing a great work, he's someone that deserves your subscription as well.
I watched this entire video and couldn't believe that an hour had passed when it was over. I guess I've progressed beyond "complete beginner" because I was hoping to see the board powered up and what would happen if a scope was attached to the TX pin or a pulse generator was attached to the RX pin. I don't know a lot about cars, so I also wondered why a car with a battery even needs a bridge rectifier to convert AC to DC. I looked up how alternators work and figured that out and learned about what inverters do in the process. This was definitely the right information for me at the right time.
These videos are among my fav where we mess with different sorts of circuits. As more of a hobbyist troubleshooter these days, I probably couldn't resist taking the next steps of firing up the oscope and LA and powering the sucker up to note behavior. I can't help myself, but for someone where time is money, that is a unprofitable approach in this case. Well done.
That is the transponder coil of a category 2 thatcham approved immobiliser. The black ring picks up the chip in the car key and relays the stored immo data/code via the coil and module to the ecu or dash clocks to authorise or deny an start attempt. Acc is accessory position ie dash lights on but not cranking to start. You can usually read the immo chip but as mentioned by others here, you’ll likely not be able to edit the bin as they use incremental registers to prevent you editing the first two lines containing the immo status
Great reason to hold onto your older vehicles. The manufacturers are doing all they can to relieve you of your ability to fix it yourself.
god these videos are such a goldmine of knowledge. why did I go through four years of engineering school when this exists?
You are watching decades of experience.
Sometimes the research hours we spend goes overlooked especially if it puts a smile on the customers face. Sometimes that smiling face gets us further along as well. I havent finished watching this video yet but i bet we figure it out.
Can I suggest you get yourself a ball of "bluetack" and use it to stabilize your board/assembly whilst attempting the surface mount soldering. Just stick the board/assembly down on top of the Bluetack and it should stay in place while you prod and poke the components. Great videos, as a novice I am learning much from them.
Damn good idea. Thanks.
I`ve used blue tack for my jobs for years. best way to hold stuff, even just to hold wires while tinning
It's great for cleaning record player stylus' too. I've checked it under a microscope and it does a fantastic job. Just an FYI...
👍
Hope you're having a good day I have found that by applying white thermal paste onto and wiping it off ic's and transistors you then can read the numbers very well, thanks for all your videos.
Great tip, tried it and works well. Thanks👍
Nice tip! Thanks. I'll have to try that.
Nothing wrong with it from the start, the bloke nicked the car !! Good effort and I felt your pain as the probes skidded off the conformal coating, perhaps your next Ali order should include a small bench vice !...cheers.
Someone else suggested Blue Tack. 😉
Or got a new key cut and forgot to keep the old plastic part with the transponder in.
Heh yeah, most obvious application for 'electronics connected to the ignition switch' is an anti-theft device and the most obvious reason for it being 'broken' is that someone's stolen the car or lost their key and doesn't want to pay the manufacturer to sort it. Take it around to your local electronics expert to see what he can do.
Many standard diodes come in chips of multiple diodes. Sometimes these are connected and sometimes it's just convient packing of separate diodes. The same is tru for chip resistors as well. All the time you were calling the diode package a bridge rectifier I screaming "Look at the schematic!" Not that I haven't done the same thing myself... I enjoy your videos! Keep making them!
Richard, I'd like to add few pence from myself.
1. Why overcomplicate things? What I mean is it took me several watch attempts to reach 33 minutes of the recording, to start to see shorts :D. How this will attract new people to start fixing electronics?
2. I'd make it more simple. But... . I've started fixing in the '90s, I've forgotten a lot and 3 times I've quitted fixing them. But, was working for 3.5 years in the computer shop and microsoldering since 2021. So, know a bit about it ;) you can say. Run as well a five-star rated with over 110 reviews electronics repair shop to make it more clear with several people helping me and over 100 active jobs.
3. How I would have done it is. First, do the visual inspection. If no findings step no. 2, check for shorts. If you don't know how to do it, start learning which components are capable of shorting circuit. If you can't find any shorts, supply voltage. If you have to apply 230V, do it via bulb. If bulb is lighting up, you've missed something. If not, no short. If you can't find a short, that means that something is not connecting, burned, or a firmware fault on some IC. And explain how to check it. And, how to replace it, or redesign it - even using Arduino, ESP32 ;), etc.
It's a bit inconsequential to the diagnosis, but I think you misread the voltage on the electrolytic cap as 6v when it's 16v, most 6v caps are 6.3v.. it would also make sense that an automotive system would run on 12V
You can clearly see it at 22:00.
yup@@TechSavvy.
Loved it Richard! Thank you for the video!
Hehehe that dual diode 4 pin device is shown on the data sheet typical configuration you found...I was screaming 😅
Love your channel and your instructing methods of fault finding without schematics 👍
ACC= accessories. With engine off.
You can listen to your radio, charge ph, ect. when you turn your key to ACC. You wont have battery power going through your alternator saving it from burning up because it's not turning the fans inside the alternator.
With the key in ACC It also keeps your fuel pump from running 👍
thank you very much for sharing, the datasheet really helped out on this board !
It’s part of the immobiliser. You need to test it in the vehicle with the key to see whether it is actually the problem.
@davidcross30 Sometimes you don't have access the vehicle or whatever a PCB comes from (industrial crane, fork lift truck, sausage making machine, F1 car engine cam shaft measurement rig, control pendant - these are just a few real life examples of things I repaired when working for an industrial electronics repair company). Sure in a perfect world you would have access to the item the PCB came from but in the real world that often is not the case.
So then you have to use other methods and that is what I am trying to show here - a methodical way to approach a PCB repair without knowing what it does. Sometimes this method will allow you to fix stuff and sometimes it wont but sometimes this is the best approach available. Your comments and those who 'liked' it suggest it is not possible to repair stuff this way. I differ in opinion and think it is surprising what actually is possible.
@@LearnElectronicsRepair Absolutely Rich you certainly can look at what is wrong on the board but in this instance with important pieces of this system missing it is almost impossible to ascertain which part of the overall system is at fault - there are inputs to this board and it provides outputs to other boards/systems.
I dare say (as an automotive engineer) that the fault is elsewhere and I would always start fault finding on the whole system.
Like you say If you can't do that, like in this case, you can scratch around to see if the components on the board are okay but other than that there isn't much else that can be done.
I MUST say however Rich. I bloody love your videos and I'm learning much more than ever before. Keep up the great work my man. And I did indeed like the video too; I always do.
Likely powered by automotive 5V reference (supply) voltage from the ECU.. Tx/Rx likely goes to the CAN bus.
Having the scan data from the vehicle, specifically Security/anti-theft/key transponder (& is the transponder in the key any good?), via a scan tool from the customer would have helped.
PS, check out and get an RTL-SDR dongle, as it is cheap and effective receiving a very broadband of RF signals .. in this case, finding out if this device is in fact transmitting.
Maybe late but at 60 I have decided its now time to learn electronics, now all I have to do is to climb this very steep hill.
I recommend the books "practical electronics for inventors" and "diagnose and fix everything electronic"
And for UA-cam channels: great Scott, Northridge fix, Andrew speiss
@@zeddpilsner4
Thanks a million for your replay and the recommendations, I really do appreciate it friend.
God bless
@@zeddpilsner4 This channel is OK also 😉
@@LearnElectronicsRepair I thought that went without saying because we were all here. Whoops, I guess I should have been more clear
Thoroughly enjoyed watching this one. 😁
my suggestion would be that the shop check with oscilloscope if the ecu pins are getting the signals and from there you can conclude something like broken key or the chip here is faulty, because as you showed the antenna is working, which often is the problem with this systems, but maybe not this time
This might be a job for the Fnirsi portable oscilloscope. You could connect it to the antenna and see if there are any signals present as this looks to be a transmitter only device. The question also is if this device is receiving the signals to transmit from the controller.
P.S.> Richard I hope you fixed up a bit those solder contacts, because while you were poking and poking and poking them,you almost destroyed some 😁😁😁
I wanted to power the PCB up and see if we could see an oscillation on the inductor - I even looked at the datasheet to see what logic levels we may need to put on the inputs to get it to do something. Unfortunately the owner wanted it back the next morning so I didn't get chance so apart from explaining how we could test that chip I wasn't able to try it. I did give him a quote to continue the job so hopefully he will bring it back in
@@LearnElectronicsRepair Thanks for the info Richard, much appreciated. I am curious how this develops.
That type of Immobilizer works by using the induction loop in the ignition to send a radio wave (similar to how wireless charging works)this causes the key to broadcast a frequency that is compared to the reference signal stored in memory.
Richard, you spent quite same time trying to figure out what the D1 device with 4 legs was, when it was clear from the diagram that is 2 diodes! and 2pins are shorted together as per the diagram
The data sheet I found describes the ic as a transformer package that’s control by external Hall effect signal.
General question, with the components of off the pcb, Can a component tester identify smd transistors, diodes, etc??
Yes any decent component tester will.
The cheap ones have a pad to put smd components directly on to check (max 3 pins)
You can see the edge of a number 1 in front of the 6 on the Capacitor
Came here to say that it was a 16V cap.
Dear Richard, first im grateful for your effort to teach us. Can you please make a video on How to analyze a laptop battery li-ions how to reset BQchip charging cycle count. Identify and replace dead 🔋. Thanks
That cap is 16 volts not 6, most vehicles have a 12 volt DC electrical system omitting big trucks, planes, locomotives, busses and heavy equipment. Anyways the device looks like an RFID reader that reads the chips in new vehicle keys. The physical key unlocks the steering and engages the contacts for the starter but the chip in the key authorizes the BCM (Body control module )computer to enable the vehicles start and run electrical system that will supply power to the starter, fuel pump, ECM, instrument cluster, stereo, etc.
Yup one like that in my van but the PCB is like 6x that in area with old through hole parts. Mine reads the transponder chip in the key, it's a glass bead type line in a dog/cat under skin chip/tag.
If the code read matches it's memory, then a secret handshake is sent to the engine ECU allowing the engine to run until the next power cycle.
It's an ac signal to the coil and the reflected waveform is monitored, three chip in the key has a coil that receives the waveform and rectifies that as a power source to transmit it's code back with.
Similar protocol to NFC but afaik the code in my key is fixed ID number and can't be written
1:45 6V... that's quite unfortunate cut off marking there when that cap is really 16V. :)
Thanks for the video
Yeah… i have one guy that keeps on bringing in single PCB’s from larger systems. He diagnosed that PCB to be faulty. No other info. With lots of reverse engineering, I normally have to tell him to bring in another PCB, on which the fault actually is. I guess that is a way to fix stuff that is too large or difficult to bring in, lol… but it is still easieer than taking all my equipment to a premise and look for faults whilst it is -40C outside. The upiside is that one learn so much from reverse-engineering a PCB, figuring out how to test it, and derive where the fault actually is. Biggest problem is always finding data sheets for those weird industrial chips….
You can use decapjelt to remove plastic vernis and see the reference smd
You are assuming the person who removed this, diagnosed this as the faulty component. He sent you on a wild goose chase.
Happy!
if chip has problem, is possible to check with multimeter on diode mode? i mean : red on ground of chip and see with the black on each pin if there is a short. Thanks a lot for your videos, keep up the good work !
Enjoyed your video I was curious where do you get those nice needle tip probes....
They came as part of a large probe kit from Kaiweets called KET05
They really are excellent, and I have used a lot of meter probes over the decades so I do know good ones when I find them
www.aliexpress.com/item/1005003727037642.html?af=ler2022
Why not do in circuit ESR measurements of the large electrolytic cap and the other one right beside it?
Yeah I could have done that also. The capacitor is directly across what I worked out to be the DC input so it probably would not cause a problem even if it wasn't there, but as I don't know where the 5V regulator is, maybe it does need the electrolytic to be present in order regulate - so yours is a good suggestion
@@LearnElectronicsRepair thanks for the reply!
@@LearnElectronicsRepair I’m still learning so, please bear with me: Do you mean to say that, electrolytic capacitors are sometimes used instead of voltage regulators? Is that really possible? Please clarify. I want to learn. Thank you kindly, sir.
Richard, I don't know if you mentioned this before, but it might help people to know that the collector always reads a bit higher than the emitter. Knowing this fact can help people know which is which and also if the transistor is faulty, because the two numbers are always very close readings. For instance, 0.768 on the collector and 0.764 on the emitter would be a typical gap between them. It seems to be something many people aren't aware of. You said that the emitter sometimes reads lower, but doesn't it always read lower? Maybe I didn't test enough, but I tested a lot an the emitter was always a bit lower. I'm curious to know if you ever found the emitter to be higher.
He has mentioned this in other videos
He has explained this in his deticated transistors video
Have you got this the right way round, as the collector is normally bigger than the emitter junction so has a lower voltage drop across it.
@@zeddpilsner4
dedicated -NOT- deticated
Invest in a Diction-ary is your best bet
and reduce the pilsner -
It helps to stay sober
Hello, i have a electronic board of kids car damaged one component have burned but i dont know whats name of it or what numer serial have, pleas help me
T1 and t2 look like ghey could be a half bridge to drive the coil. Very hard to fault find this as you need to be able to tell it to turn on and read the key. So you need the data format for the coms bus, and if chip has an issue then your probably need to reprogram the ecu. These are mosty a no win
An old-fashioned example of when someone had to find an address and there was no GPS (schematics)
Big storage capacitor is 16V not 6V. No 1 is barely seen at the edge. I think the problem is not in the Cct. Owner of the car may have used a mechanically duplicate key instead of using the original smart key to start.🤭
Thanks, my bad eyesight then. The thing does run on 5V though as proved from the datasheet.
@@LearnElectronicsRepairYou are correct!, Sorry if I've being rude to you, b'cos my English is so poor. I'm 52 now and I found you are a very experianced helpful technician from all arround the world. what do you think of my 2nd guess?
😀Hooray!
Richard.......😳😳
Where is one of your oszilloscope 😱 to do measurements on the pcb 😭😭😭.
But,,, the video is instructive and intresting👌👍👌👍👌🖖🖖
You misidentified the large capacitor as 6v it is 16v which would fit with most automotives being 12v
Check timestamp 22.18
its a throttle hall sensor off e scooter which run on 5v rail
ok, but then where is the buck converter or something similar to lower the voltage? I'm pretty sure the cap is 6 volts
@@ДимитърАндонов-ъ7е its possible its a wowzer for a wigwam
@@ДимитърАндонов-ъ7е no it's not ! Look at 22:06 , you can see cleary 16V
@@BjornV78 i still dont see how its 12 volt line when the chip is working max up to 5.5 volts? Do you see some power supply or something that will drop the voltage to 5? because i dont see it. It can be that they used the capacitors they have in stock, as someone said the 16volts are used almost anywhere, and using higher voltage capacitor than the rail is using wont hurt anything
That little four-legged device was a bridge, it just had the two AC corners strapped together, so two diodes in parallel “up” and two diodes in parallel from ground up to the signal line.
Generally I wont take on this type of job….the reason? Because this is not the WHOLE device, but rather just a part of it….and the whole…I.e. the whole rest of the vehicle works as a unit and..as the bloke who owned it said, he was not even sure the real fault was not somewhere else in the other part of the circuit you did not get to see.
There is another way to look at it though…if you have the gear…this is automotive, nowdays a lot of automotive seems to yse the CAN bus standard….I think another place this is now used a lot is in disco/night club/theatre lighting control. So IF you have test gear that will generate and recognize CAN bus packets….and a lot of contemporary oscilloscopes do have various digital protocols that can be selected in triggering options…and if you had a signal generator that did CAN bus too…then you could concievably do something meaningful with it…but without such gear I feel I,d be wasting my time.
This is what makes this sort of hybrid comms or even servo control stuff so unrewarding…take an electronic washing machine or E-bike or some other such part electronic, part mechanical, part hydraulic circuit/system where opto interupters or hall sensors and motors connect the electronic bits to the other thechnologies…these have to be worked on as a system, just looking at the electronic bits in isolation to the rest of it is generally pretty unproductive or inconclusive…as this was.
I got landed with a boat controller the other day, it had dozens of inputs, all protected with varistors, transzorbs and inductors, it had dozens of outputs too, from bug mosfet half bridges through filter networks, some PWM proportional, some just on-off digital. Took me a good hour and a half to get the lid off and dig down through the compliant goo to the board. There was a big micro, with Rom And Ram….I identified the power input and hooked it up to the bench supply, I found the crystal of the master clock…it eas running so the micro was working…And I would have done the same there with yourgadget, Put 5v across that electro and the CRO probe straight onto that ceramic resonator…if is wad oscillating i would have taken a quick look at the data out and waved an expendable RFID card over the “Antenna” …um, coil…if the trace changed at all on the scope I’D have deemed it a “goer” and told the bloke to look elsewhere…back to the boat controller…I eventually found a Lithium Primary cell that obviously held up some volatile contents in one of the memories…it eas dead flat…so I assumed the firmware was gone and went no further without gear that could specifically communicate with it.
I susprcted the bloke who owned it simply scrapped it and forked out for a whole new unit when the onternal battery went flat. It wax biught to me by a mutual friend but I was given no fault discription or even any pressure to repair as he had already replaced it and just thoufgt I might learn something from it. I suppose I could put a new primary cell in it and take it back to him to try, but that wiuld be all. I imagine such a thing failing whilst you were far out off the continental shelf….I’d definitely want a far more low tech and less fault prone system to get me home.
This is why I generally just wirk on complete electronic only sysyems that are self contained and I can get up onto the bench!
I like it Richard! Thank you for sharing your thouts in such kind repares, wich is a lot in our days
Heya yes very educational even wen you don't know the working of the part you still can do some measurements of the componments on the pcb to see if there would be a fault componment have not tought about that route thanks
Replacing the chip probably won't help, you also have to program the original RFID key code in the vehicle computer, if it is corrupted. It is very seldom these RFID readers become defective. I make and sell a lot of RFID lock system, and it is very rarely I see a defect.
I would agree with that ans suggested to so much in the video. The datasheet for this chip proves it is purely an interface between the key code generator (wherever that is on the vehicle, in the ECU?) and the antenna that communicates with the key fob. Or at lease that is how I read the datasheet and typical app. As you have more specific knowledge of this system, could you elaborate on why I can't replace that chip with another one? As an aside I don't actually believe the chip is faulty, I basically just proved that nothing else on the PCB is faulty, therefore the chip is the only thing left. Of an the crystal resonator. As I mentioned at the end the customer picked it back up before I could complete the investigation how I would have liked to. Hopefully he will bring it back
@@LearnElectronicsRepair Unfortunately I don't know much about car computers and where the code is stored. I don't do cars. But the reason I don't think the chip is faulty is because if it is you would expect that the car bus/computer would return some kind of error code if it can't communicate with the immobilizer reader. This sounds more like a job for an OBD tester considering how complicated a modern car operating system actually is. I think this fault could be everywhere, and I don't believe he has sufficient evidence to say that the reader circuit is faulty.
The circuit you have is actually not just a reader, it does also have the ability to *write* to the key. Because the EU demands that all cars have the ability to write/prepare a new key blank. So your circuit is actually a part of a more advanced system making your circuit a more or less dumb passive circuit that just facilitates the communication with the key rfid.
THe chip is S57780MA - looks like a TI chip... wonder what the cost would be... looks like maybe $18?
42:46 A really large soldering tip on a very small component ?
I would recommend to buy 1) a board holder, and 2) a solder station with a small pointy tip. Your tip is much too big. For SMB even totally unusable. The current one looks as those old ones without temperature control. If it has none you should get definitively a solder station with temp control.
I do like the vids and i think you are great!! but dude you frustrate the hell out of me shorting stuff out with those long probes.
18:10 Replacing a IC that is part of a car electronics system is not an option anymore these days, almost every circuit in a car is connected to the ECU (main computer) and use CANbus fault diagnostics and has a serial number attached to it. The guy that ask you to look at this part, has propably got a high repair quote from the car dealer, and didn't want to pay for that. When such a part like this RFID ignition slot is replaced at the car dealer, the ECU has to be reprogram to accept the new part, and also only the car dealer knows the exact frequency that match the key fob of the customer. Otherwise everybody could ordered this part online, and could start a stolen car.
that's look like from old car, and many times you can just replace the part, it don't look like CAN communication and also this board and antenna are just rf transmitting and receiving, they don't do anything to the signal
Maybe chip is readable? Would you need special programmer to copy them?
@@KennisFix The datasheet says this is a dumb interface, not programmable. As far as I can tell
every'one' NOT every'body '
Ask yourself this simple question
How many of YOU are there in existence in this world ?
Learn that Legal and proper grammatical Legal English
a BODY refers to a DEAD entity
You will find them buried in the cemetery.
Go and visit and while you are there - pay attention to HOW
the name of the CORPSES is written.
HOW something is written is CRITICAL - but the ZOMBIES
in this world do not notice the detail as they are semi-conscious.
One has to learn Law at a high level and Latin to be proficient
and competent in the English language.
Common Street English is Peasant level English - That is what
is taught in CORPORATE GOVERNMENT indoctrination
institutions known as School
Good luck and good bye
Learn the above lesson and teach it to the ignorant masses
whilst work of this type (part of a system/not self contained module - especially of unknown functionality) can be potentially useful brain teaser exercise, its otherwise rarely productive and most definitely not economically viable. simple circuit with only one marked, not-programmable chip that has available datasheet - and still got pretty much nowhere
oh pleeeze, can you stop the board skating all over your bench. FIX it in place. And use probes correctly, aim down from the top, not very obliquely from the side so that you are skidding off the contact (solder) all the time.
Hes trying to steal cars. Lol. JK!
It looks like a horn carbon ring from an automobile?????
NIC? Network Interface Card? Sorry it was HIC.
when you poke the solder pads.. i cringe so bad.. as it drags across the traces and leaves a crater in its wake... scraping the whole board up.. ugghhhhh... cringe, cringe, cringe..
but i love ur videos.. please keep up the good work..
How do you suggest I get a connection through the coating on this PCB without poking holes in it, or make some required tests without getting a connection. I'm all for improving my technigue as regular viewers will know.
@@LearnElectronicsRepair I am a regular viewer.. subscribed & like every video.. it was not a put down.. i know there was a coating.. just under microscope.. u can really see what the probes do... that's all i am saying.. i love your videos, please keep up the good work.. I am a beginner in electronics.. (hardware).. (I've been a programmer for 27 years in many languages (software)).. I am trying to learn everything i can.. the basic components & how to test them.. can you do a beginners run through of common components, how to test them with multimeter.. & find faults & what mode used.. i know u have a few vids like that.. but they were drawn out & i was still confused at the end.. something more straight to the point, focused.. using your experience & pitfalls, & how to know if a component is bad in-circuit..
that looks like a hall sensor throttle off e scooter or bike
looks like the transpoder of a car to me :D
Looks like a transponder and datasheet backs it up.
So, he can pluf this hacked module into any TESLA EV and steal it, in 60 seconds ??
0.628????
watch his video for the esr meter and you'll know
The value of 0.628 is used as a conversion factor when calculating the impedance of an inductor based on its equivalent series resistance (ESR).
@@svetlinbarzev9110 Or tell us like the bloke below.
@@andymouseit's just very interesting video, where he explains very well and detailed. That's why I recommended watching it ...
Excellent vid.
I didn't get your repair technique that takes 1 hour and ends up not knowing the reason behind the fault. Sorry, i appreciate your channel but looks like your video's title is a clickbait to me.
Also testing unknown components onboard is not the right technique.
mby you need to take some basics videos/books so you can understand better what he is talking and testing
This is not Richards target.
Repair Repair Repair Repair.
Money Money Money Money
Richard explains and bring knowlegde to the viewers.
I agree. I frequently watch Northridge fix and coming from there to watching Richard fumble around with a tiny board and no pcb holder was just painful to watch. The order at which he was checking components was also questionable. Checking for low resistance on resistors but not on the electrolytic cap. No ESR measurement on that either
@@zeddpilsner4 lol comparing Northidge fix to Richards is like comparing Ferrari to fiat in favor of Richard. Alex is just good at soldering and he is very bad at troubleshooting, and on the other hand is Richard who has very good experience and can fix most of the stuff with his methodical approaches. Alex often cant repair anything that he never worked on :)
@@ДимитърАндонов-ъ7е well i have to agree that Northidge is awful. Search for "Electronics Repair School", he's doing a great work, he's someone that deserves your subscription as well.
Can you translate your videos in french please
X
"promosm"
16 volt is the electrolytic cap voltage marking.Should be pretty logical since it is from a car that all know run on 12 volt battery.