How to spot a fault in a circuit, like a pro : hands on electronics [1]

Рет қаралды 149,816

2 жыл бұрын

In this video I show the method to find out a fault on an electronic circuit board. In the specific case we have an ESC (Electronic Speed Control) that is used to control a washing machine motor (used to drive the spindle of a lathe) and somewhere in the circuit there is a faulty contact. It turns out it was a bad soldering that caused an uncertain contact, making the motor to start and stop randomly. The video shows the procedure to spot the exact point where the fault is present.
Wonder how to #faultfinding without schematic? Watch this video too: • How to #faultfinding #...
For more related/complementary content over my videos please visit my website accidentalscience.com.
Watch the full series of electronics: • How to spot a fault in...
Follow me on Facebook or Instagram
Website: accidentalscience.com

Пікірлер: 77

@AccidentalScience 23 күн бұрын

Wonder how to do this same thing BUT without schematic? Watch this video too: kzfaq.info/get/bejne/r9CoqLCosbSbqn0.html

@thomastaylor2450 Ай бұрын

I have never done this , I read several sites to find out how to do it, then I came here and learned 10x more than all the others in only 10 min so thank you!

@d.e.c1609 5 ай бұрын

This is the very first step (in) troubleshooting. Great job! We don't have (time) to guess.....

@will_doherty 2 ай бұрын

Very nice demonstration of fault finding using schematics. I find that schematics are mostly very difficult to find for anyone outside of the industry, so I have to use different methodology - firstly check all electrolytic capacitors for signs of leakage/doming and replace any that have failed, then have a close look at the board - particularly components and soldered joints for signs of failure (under a microscope) - the fault that you had I would have found readily, and maybe in less time too. Next, look at power supply circuits and check that they're functioning as they should, and check all discrete semiconductors Then locate blocks of circuit that I recognise and test the components in each block. By this time most problems have been fixed. Checking the datasheets of unknown multi-pin ICs often comes up with sample circuits, many of which have been utilised by circuit designers - that makes some fault finding very straightforward. If after all this the fault remains and a schematic is not available, it's probably time to invest in a replacement pcb...

@AccidentalScience 23 күн бұрын

If you are interested on how to proceed without schematic I made this video: kzfaq.info/get/bejne/r9CoqLCosbSbqn0.html Hopefully it will be interesting for you. Greetings from the Alps.

@katiefinnegan4649 2 ай бұрын

I was so invested in this!!😆 well done

@dporrasxtremeLS3 4 ай бұрын

Yes! This Takes the mystery out of the equation! Thanks!!!

@AccidentalScience 4 ай бұрын

Thanks for commenting. Happy new year.

@jimmy_jamesjams_a_lot4171 2 ай бұрын

Very nice chuck fixture on that lathe. My main hobbies have migrated from EE over to Mechanics recently. I had never believed myself to be an innovator until I finally began with a few diy opportunities in recent times. I am saddened by the lack of instructions included with test equipments recently. So I am grateful for troubleshooting demonstrations such as yours. Accolades, and I wish you luck with your lathe!

@AccidentalScience 2 ай бұрын

Thank you mate.

@consolechips 8 ай бұрын

You missed another dry joint above the broken pad you found … look at 12:14 on the top right it has cracks all the way around the pad.

@AccidentalScience 8 ай бұрын

Well spotted.

@nevinkuser9892 3 ай бұрын

The whole thing looks a bit sloppy. The guy must have been making it right before lunch.

@neodiy Жыл бұрын

How do you always get access to the schematic diagram of the circuit...there is serious difficulty to find for certain specific devices

@AccidentalScience Жыл бұрын

For unknown circuits the only way is to reverse engineer. It takes time and sometimes it's really hard when BGA ICs are involved. With multilayer PCB very often the inner layers are just the GND and positive (and negative if the PCB has 3 inner layers).

@abdelhamiedsarhan6308 3 ай бұрын

@@AccidentalScience good idea that I have from your video thank you

@distort89 Ай бұрын

I specialize with game consoles. The only thing I have difficulty finding is ps5. Most others have either been leaked or have been reverse engineered by someone. Most pcbs are multi layered and require an xray machine.

@AccidentalScience 23 күн бұрын

Eventually I made a video about the case where no schematic is available. I thought to add a further reply to your comment with the hope it will be helpful for you, this is the link to the video: kzfaq.info/get/bejne/r9CoqLCosbSbqn0.html . Thanks for following my channel, greetings from the Alps.

@jluke6861 4 ай бұрын

Thank you for the great video.

@AccidentalScience 4 ай бұрын

Thank you for commenting. Have a happy new year.

@user-iv4js9fw2e 3 ай бұрын

Is there any way to test signal without oscilloscope and a multimeter

@MartinLDeLoach903 3 ай бұрын

Those that don't know that triangle thing on diagram is called a op Amp, operation amplifier..

@laidman2007 7 ай бұрын

Thank you.

@AnuroopMusic Жыл бұрын

Nice 👍

@nevinkuser9892 3 ай бұрын

This is exactly how you would systematically work through a car's schematics.

@MECANICA_NA_GARAGEM 2 жыл бұрын

Hello. the electrical circuit you are using, in addition to the motors (why two?), is it from a washing machine? What changes did you make? From the schematic drawing shown in the video, were the changes in the handwriting? can help? I'm also building a mini lathe and wanted to use a similar motor. but I'm having trouble controlling the rotation of it. Thank you for your attention . Cheers I forgot.... congratulations one more subscribed

@AccidentalScience 2 жыл бұрын

Thanks. The circuit is my own design. Look at previous videos where it is described as a driver for washing machine /universal motors. I used two motors to get more power.

@brianlittle717 3 ай бұрын

I like to use a plastic ink pen with the writing part of the pen retracted when I touch the board. The eraser part of a pencil also works. Never touch it with my fingers.

@paulf1071 4 ай бұрын

Thanks for putting this video together 💯 Did you have much trouble sourcing the schematic diagram of the ESC circuit?

@AccidentalScience 4 ай бұрын

Well, no ...it's my own design :)

@paulf1071 4 ай бұрын

@@AccidentalScience Wow, nice work!

@AccidentalScience 4 ай бұрын

@@paulf1071 thanks. If you are interested, in a previous video the circuit has been described. It should be available even on my website.

@AccidentalScience 23 күн бұрын

If you'd like to know how to proceed without schematic watch this video: kzfaq.info/get/bejne/r9CoqLCosbSbqn0.html

@hobonickel840 3 ай бұрын

I've been trying to learn about using dmm because recently had a bad hexfet on tennisball machine PCB.. that's how I found your awesome video. However, now I'm more interested in that spindle head on the lathe.. Is that a Taig 5c or did you diy the the spindle, bearings and housing? I'll have to look through your channel and see if there's more vids about the lathe. I'm trying also to decide which route to go with a home hobby lathe and the Taig 5c spindle head is $600 ...that's a nice looking spindle/head and perfect for what I'm looking toward for making pool cues update: ok nvrm, I found your video regarding the lathe ... luv it

@AccidentalScience 3 ай бұрын

I wanted to try the route of making a lathe from the perspective of J. de Vacaunson in 1700s, and studying the Whitworth method for achieving flat surfaces. I was wondering how they do reach precision from scratch. So it was a long and insightful journey. I ended up having a quite precise and very strong bed and carriage (with no compound on purpose). But I also experienced a lot of setbacks. If you want to build your lathe, be aware that if it shall be a decently high precision machine then it will be a long and steep journey. The setbacks I experienced were not strictly related to the lathe, but the complexity of the job took its toll. Hope to be helpful, and good luck.

@hobonickel840 3 ай бұрын

@@AccidentalScience Let me ask ya ... I have steel track rails from old Belsaw sawmill ... they look like railroad rails .. do you think these could be machined down for carriage rails?

@AccidentalScience 3 ай бұрын

@@hobonickel840 hard to say, I don't know that sawmill. Generally steel is a good material even though it sports a higher coefficient of friction than cast iron. Cold rolled steel is prone to deformation if, let's say, you make a hole in it. Once made flat the rail should not be worked further: no machining, no welding.

@hobonickel840 3 ай бұрын

@@AccidentalScience so it's better to not to flatten and use the steel rails for precision rails??

@AccidentalScience 3 ай бұрын

Not necessarily if you plan your work well. For example if you need to weld the rails do it before flattening them. Also consider annealing the part in an oven once it is welded, and only then go for the flattening job. Another option is to do all the required holes, then flatten the rails and finally bolt and glue together using locating pins and strong epoxy resin. p.s we are off topic under this video.

@dashley2525 2 ай бұрын

My 10.2 PowMr will harvest so Load is being met but battery is not being charge till about 1800 w. The PV input readout is an arbitrary .5 kw till about 1800 w PV input. No one has had a clue why so far. A replacement 6.2 kW PowMr works perfectly. So the issue is surely in the 10.2 unit. Issue existed at initial startup.

@lennym1273 2 жыл бұрын

Good advice just one problem, most of us don't have a scope lol...

@AccidentalScience 2 жыл бұрын

Yep that could be actually a problem. However because in this case we mostly have continuous signal in many points we could have been able to find *this* partcular fault even using a voltmeter. Though for a more general methodology even a simpler scope is a must. Thanks for commenting, have a nice year.

@rabarebra 9 ай бұрын

You could actually just use you eyes looking for bad soldering joints first. Problem solved. No need for $20000 scope equipment, just some solder.

@NoSpam1891 4 ай бұрын

I just got a good little scope on eBay for less than $25 shipped. Not a huge bandwidth but you rarely need that and I have a 100 Mhz scope if I need it. The new one slips in my pocket.

@Necrozene 3 ай бұрын

Huh? You missed that on initial visual inspection? Oh dear. Great fun though, following your subsequent logic!

@ronbianca1975 2 жыл бұрын

Very good my friend! What is your native language? Stay healthy.

@AccidentalScience 2 жыл бұрын

Ohh it's complicated, it's a dialect with some inflections went from an almost dead language. I even mostly forgot it.

@UdayKumar-xl5gp 4 ай бұрын

Good explanation with ckt diagram , but what about without ckt disgram

@AccidentalScience 4 ай бұрын

Thank you. You made a good question. I'll try to address it in a video.

@reylambarte5615 4 ай бұрын

During the visual i noticed that lots of components were desoldered. If i am to start with signal checking after verfying the power supply i will start at the output and go backward checking the inputs. Desoldering should not be performed until the faulty component is positively identified.

@AccidentalScience 4 ай бұрын

There were no desoldered components! This is a configurable board and what you think is a desoldered component is actually a config or modification component.

@reylambarte5615 4 ай бұрын

@@AccidentalScience okay, but the work is dirty. What do you think?

@AccidentalScience 4 ай бұрын

I had to give a look again at the board and at the video to get what you mean, since this stuff is 2 yrs old. The board has some significant modifications on top of its configuration setup. So, again: no desoldered components for the purpose of finding the fault. Indeed one of the points of the video was to follow the signal path (look at 3:16) . Yes I convene that the modifications are not aesthetically tidy, but they are firmly secured and functional.

@reylambarte5615 4 ай бұрын

@@AccidentalScience yap, thank you, i have a long experience on manufactured controls for the manufacturing equipment and had worked on poorly designed circuits that need some modifications, but the circuits that came direct from the manufacturer, modified or not it should be soldered clean.

@timwhite7127 4 ай бұрын

You took the words right out of my keyboard. I would at least start midway to eliminate half the circuit from the git-go.

@LookOutForNumberOne Жыл бұрын

Hi, are you in the UK??

@AccidentalScience 11 ай бұрын

No longer.

@LookOutForNumberOne 11 ай бұрын

@@AccidentalScience All good, np

@kolbakolba 2 жыл бұрын

2021 problem 2022 no problem

@ebenezeradentwi9062 2 ай бұрын

How do you get the schematics Sir?

@AccidentalScience 2 ай бұрын

It's my own design.

@HereOnYouTubeCommenting Ай бұрын

1:00 Broken solder joint .... or cracked circuit board.

@chrisleech1565 2 жыл бұрын

Aha

@EvgeniX. 2 ай бұрын

well what if you're trying to fix a random board with no schematic where you don't know the expected values? the video tells nothing about that 😐

@AccidentalScience 2 ай бұрын

Next video.

@alexlukwago3070 Ай бұрын

in africa we replace the board at once

@OMNI_INFINITY 3 ай бұрын

Appropriately named channel for somebody that didn't discharge a large capacitor after unplugging board from wall outlet

@geoff4009 3 ай бұрын

You mean that 16 volt capacitor connected to +/- 6 volt supply? Yeah big danger mate, watch out!

@brianredmond4919 27 күн бұрын

Shocking

@johnsmith-tr3dh 4 ай бұрын

I think this guy went to the Italian university "Wossamotta U"

@viking1ur Ай бұрын

Like most youtube video U talk about everything that do not matter.......did u forget to tell about your cat and your grandmother

@amadoujallow429 Ай бұрын

What is you contact

@bussi7859 8 ай бұрын

I spotted you, ,,