The 12 Most Common Electronics Faults : How To Diagnose And Fix Them

[@r.perkins2103]

My check list is- connectors, anything that moves, heavy items- check solder joints. High stress items- volts or current. Likely fault conditions, thermal stress, age. Corrosion. Good video.

[@smartchip]

When maplins ended, then it was evident the age of the fix it yourself, learning to repair etc, It's was a better time, Godbless you for your contribution to keeping the skill and knowledge alive,

[@roberttown2816]

I miss Maplins😢

[@theboogeyman408]

Thanks! I love your videos and have learned a lot of stuff watching them. Just a little something to give back to someone who gives out good content that adds VALUE! Thanks, and keep the videos coming!!

[@LearnElectronicsRepair]

Thank you so much.

[@bulwinkle]

I used to repair office machines, electric and electronic typewriters, calculators, dictation machines mainly. The first port of call in no power cases was the mains plug and cable. Often the plug was incorrectly wired and, or fuse blown. Another common failure was that on equipment where the power cord entered at the back conductors were broken where the device had repeatedly pushed to the back of a desk against a wall.

[@Starchface]

You discussed high-voltage components with a characteristic missing pin for isolation. That information is quite a nugget of gold. I had not consciously thought about it until this moment. I find that rotary potentiometers indeed often fail on older equipment and that liberally spraying contact cleaner helps for awhile. Trimmer pots are tricky because they're intended not to be touched after factory calibration. When they're bad and you lack service data, you have no way to set the value after replacement except by trial and error or guessing. But the linear potentiometers I find are absolutely horrendous. I can literally say I've never had one that wasn't marginal or outright failed. Cleaning these is generally useless, and finding the right replacement is not trivial. Thankfully designers avoid these in modern equipment. Encoders are more complex but far more durable. Lots of good info. Great video Richard.

[@darrenbird2526]

Hi Rich! Thanks for spoiling us again with GREAT content! Look at the amount of views and likes you get in such little time. It's because you give such great advice. You take your time to explain things to us in detail and in ways we all can watch over again so we can understand. No matter how much experience we have or don't have and in a way we can understand. You know when there's a possibility that some of the things you try and teach us some of us may not understand and then you take the time to get out your pen and paper and give us explanations and possibly something that the majority of us can understand. I'm not pissing in your pocket mate but this is one of, if not the best channel to learn electronics and I sincerely mean that from the heart and I thank you for teaching me about something I'm passionate about. Some other KZbinrs need to watch your videos and learn from your generous techniques. Especially when they charge a lot of monthly donations to learn less than what you reach us for free. I for one am very proud to give you a monthly donation. It's a pity more people didn't do something similar or at least buy you a cup of coffee for what you teach us, as you are a rare one that doesn't beg for likes or even subscriptions so you can fill your pockets with KZbin money. I for one thank you from the bottom of my heart for teaching me about something I'm so interested in. Thank you Rich!

[@sharymens8187]

Yes! He is amazing!

[@LearnElectronicsRepair]

Thank you, that made me blush. If anyone really would like to help me earn a bit more but for no cost to themselves, when ordering anything from AliExpress look at the URL and delete everything after the question mark, replacing it with af=ler2022 So for example a mosfet kit like this one www.aliexpress.com/item/1005007134551393.html?spm=a2g0o.productlist.main.7.24fd60a9MxTi73&algo_pvid=d0e49806-4b77-403a-8f83-ea36de587680&aem_p4p_detail=2024120510374417838518589759570004673280&algo_exp_id=d0e49806-4b77-403a-8f83-ea36de587680-3&pdp_npi=4%40dis%21EUR%215.31%215.31%21%21%2139.69%2139.69%21%402103890917334238649242381ead87%2112000039536095740%21sea%21ES%21930356704%21X&curPageLogUid=zvUZKPwPhKVM&utparam-url=scene%3Asearch%7Cquery_from%3A&search_p4p_id=2024120510374417838518589759570004673280_2 edit the URL to www.aliexpress.com/item/1005007134551393.html?af=ler2022 and I get a bit of commission though you still pay exactly the same price. If you all did that when ordering it would make a big difference to me and cost you nothing but a few seconds of your time 😉

[@georgekashuba1656]

I have been a electronic technician for 45 years and worked on TV, metal detector, many other products and most faults i found were zena diodes,noisy resistor, opamps,fuse, transformer, phono jacks.

[@heyjohnsmith]

Followed your powerline repair video and replaced 3 Caps with my TP-Link pa7010. Unfortunately didn't work out, notice there was also some red gunk under the smd bridge rectifier, planing to replace that next. Will check out this video first for more info, thanks!

[@tsarodavid9730]

Thank you for this great work

[@psmith6388]

I've had 3 or 4 Behringer UMC202, 204 and 404 soundcards all coming back to the warehouse faulty. All of them have various blown capacitors. Anyone else seen this? Great video, thanks!!

[@hapskie]

Behringer is known to use subpar components in their equipment. Especially the capacitors can be of very low quality and are prone to fail.

[@C5films]

Great to see you buddy. Hope the weather there is better than here!

[@LearnElectronicsRepair]

about 26C daytime at the moment and 19C night time minimum

[@Alex-M0OOV]

Never heard of capacitor plague before, thanks for sharing that! I'll look into the story of industrial espionage, sounds fascinating.

Unfortunately in a perfect world this would be the case but I have seen this problem way to often. Why? Simple, theft ! Years ago a large capacitor manufacturer slole a formula for capacators from a liter manugaturers computer system. The formulat they stole worked just fine for about 6. Months to a year then bang. You would not believe how much equipment these stolen formula caps took out. They where green in color and came from Korea I think but could be wrong. Needless to say they got caught enbarassingly ! So yes it happens bit most of that equipment failed a decade ago. Ya so it happens. I find most common problem is driver scrs sized to just right for the job at hand with no headroom. I usually just change them to one size bigger and it's problem solved forever. Anouth common problem is using small circuit board traces to carry way to much current. They usually just burn off the board over time so easy to find. You would think dirt containing metal would do but I worked at a steel manufacturer and I've seen computers with a half inch of metal dust inside from grinding parts. Most of these computers still worked ! I'd just clean them out, put filter cloth on openings And return to service. I've seen some with a inch of metal dust inside and the matchine somehow where still working. The dirtyest computers I've have ever seen in my life with the worst possibledirt type still working. If I had not seen and PM'ed such machines I would not believe it was possible to survive in such a environment. I fixed industrial electronics for 40 years now.

[@CorvusCoroneCanisLupusSawel]

nice to see an english bloke talking about electronics as change from all the americans. you can tell this guy is english as his missus is sitting in the background completely ignoring him. it's a british thing 🤣 i'm delving into electronics a little more in my later years, so this is very helpful. bless ya, mate! 👍🏼

[@davesdigitaldomain]

I agree with you on the electrolytic capacitors, unfortunately most manufactures today still use cheap poor quality capacitors and that is why they are the most common failure. if they made them like they did in the 70s and 80s like for instance Sprague and Mallory capacitors they would last for decades I still have some vintage equipment that I use regularly like my old Tektronix 465b that has these old capacitors and they still test fine today 40 years later.

[@8BitNaptime]

Yeah it's all over the place in terms of manufacture year. There are some brands that are bad in equipment from the '70s and '80s. I forget the brand but these aluminum electrolytics in a dark purple case are all bad, right next to ones in light blue cases that are perfectly fine. You have horrible little tantalums in yellow drop packages that will short out on boards from the 1980s while the aluminums are perfectly fine. Then in modern equipment you get these tiny low-ESR electrolytics that all bulge and split and leak, but I suppose they're under-specced for their role as the output filter cap of a switcher. I replace them with random Chinese low-ESRs from a aliexpress kit and it revives the board for a while I guess.

[@Dutch_off_grid_homesteading]

Heya, yes 1 more great video aboout fault finding's

[@georgeprout42]

MLCCs can fail open circuit as well, but because the device usually carries on working, nobody ever notices. Same with surge protection MOVs, they're great at protecting against power surges, until they aren't doing anything as theyre open circuit. And theres no way to know if your expensive "protective" extension lead is working or is now just a regular extension lead without a destructive test.

[@marcrlg5551]

Thank you, very usefull.

[@giuseppemangeruca6898]

Thanks Richard 😊

[@LearnElectronicsRepair]

Your'e welcome

[@greengrayradio1394]

Good info! About electrolytic caps, yesterday I was measuring some 22uF 25V Philips axial 'lytics bought ca 1991. All had the same high ESR (9-10 ohms@100kHz, 6 times higher than recommended) I wonder, could they have been affected by an early "capacitor plague" ? Earlier caps, same value, from them read less than 2 ohms ESR

[@luizdiefenbach]

Very good and informative! Thanks a lot Richard👏👏👏

[@jamkpa]

Good stuff.

[@00Skyfox]

Regarding cracked dry solder joints, do you find those to be more common or less common with modern electronics that primarily use lead-free solder?

[@rgbplumbinghilton]

Definitely common in lead free. Dries out and cracks. It is the most common fault of older modern pcb after Capacitors, diodes and mosfets.

[@patrickcraenen5163]

Hello Richard, Very interesting video, especially for beginning repairers 🙂 Maybe you should mention that when you replace a trim pot for a critical setting, you should set the new trim pot to the same position or, if possible, measure the old trim pot with an Ohm meter, and re-adjusting the circuit will probably be necessary. Cheers!

[@LearnElectronicsRepair]

Yes that is worth mentioning, thanks

[@hadjnabil4811]

thank you.

[@thomasshi9138]

Although the BGA professional soldering station is not very expensive, it is bulky and not easy to carry. You have to put it in the room.

[@Cobra1-d8j]

As an ex electronics technician, the train of thought relates to the age of the equipment,, is the equipment used regularly, is it subject to rough use , does it have inherited problems by design , is it kept in surroundings that could lead to it's demise ?? However there is a table of most likely culprits also,,. There are numerous reasons for a technicians individual approach to faults!!😮

[@Fizeeek]

Hi. Great video! Could you possibly help me to identify the specifications of two surface mount aluminium electrolytic capacitors? Top 35 Middle 4.7 Bottom WBS The other capacitor is: Top 50 Middle 1 Bottom WBS. I have spent many hours searching the internet for spec sheets but can't find any. The capacitors are part of a control pcb from a 15 year old AMANA MYTAG fridge freezer. Any assistance would be much appreciated! Thanks.

[@thomasshi9138]

I once replaced the volume switch of a loudspeaker. It was working near the maximum volume and it failed after a while. I spent 60 RMB to buy a new switch from the manufacturer, and it seems that there is no such problem anymore.

[@thomasshi9138]

To repair the motherboard and south bridge chip, you also need to prepare a BIOS chip reader and BIOS program modification software.

[@perkulant4629]

I’ve seen a load of super capacitors recently covered in a white frosty substance. No sign of moisture anywhere on the pcbs. Wasn’t sure if they had leaked slightly.

[@perkulant4629]

Almost like a powder I should have said.

[@j3ffn4v4rr0]

@@perkulant4629 Yep, sounds like a leaky capacitor...that's the electrolyte that came out and dried up.

[@j.lietka9406]

Is the "Dry" solder joint the same as a "Cold" solder joint?

[@LearnElectronicsRepair]

Yeah different name same problem 😉

[@j.lietka9406]

@LearnElectronicsRepair yes, thank you again! 🤓

[@thomasshi9138]

I only buy electrolytic capacitors from well-known Japanese brands. I have never had a malfunction after replacing a faulty capacitor..

[@sharymens8187]

does tapping during reflow really make a difference?

[@LearnElectronicsRepair]

Well it won't do any harm if you do it right and it may help. Perhaps I should do some experiments...

[@sharymens8187]

@LearnElectronicsRepair just curious haha thanks!

[@sharymens8187]

Pressing down might also cause balls to blob together I think

[@oefzdegoeggl]

About this "don't replace a fuse with a wire": Does that also apply if the wire is a "proper calibrated" one? 🤔😄

[@JustInspiredKent]

Lol, someone's been watching another KZbinr. :))

[@chantalslut]

Does a nail qualify as a wire? We all done it.... :-)

[@DrFiero]

@@chantalslut - As long as you never replace a 16ga nail with a 2 penny! Hahahaha

[@perkulant4629]

Proper calibrated wires are ok when there are other protection devices in play.

[@andymouse]

No Idea how old you are but we used to have to buy fuse wire and it came with different current carrying capabilities, this was typical for house distribution panels...so don't laugh !! there is calibrated wire !

[@rogerfroud300]

Some designs are extremely poor and prone to regular failure. Electric Gate controllers are classic examples of this. The relays get burnt out and need replacing or the board being changed. If you look at the circuit, many of these have no protection to prevent arcing when the relay contacts open and the motor back EMF goes sky high. Connecting a suitably rated Varistor across the DC motor terminals solves this problem. I reckon Gate companies make a fortune out of this.

[@thomasshi9138]

Capacitors near power components are prone to damage.

[@user-sm8wo3dj5z]

Problem is no shematics, some blown parts cant be read for the value or number

[@kpilab1415]

nice

[@user-tn1hk6zm2freedom]

They fail because of voltage change. A full battery puts out more volts and current then a battery run down. If all circuits had voltage stabilizers they would not fail. A steady voltage of the the needed volts is what is needed and another point is if the voltage is held at 12 volts in stead of it being up and down by the amount of charge in the battery the battery will discharge slower making the battery last a lot longer. I have tested this and it proved to be true.

[@johnnyyo3299]

que pasó con la traducción automatica??

[@PaulBaur]

I prefer the chocolate MLCC over the strawberry.

[@LearnElectronicsRepair]

With me it depends on my mood at the time...

[@OnStageLighting]

The Internet : Capacitors! Reality : Mostly Not Capacitors. A high proportion of my customers have a line that goes like "I looked it up online and it said some capacitors need replacing." For literally any fault..

[@DrFiero]

Unless it's an older Samsung monitor. Then.... it's the caps. ;)

[@carlosedwardos]

the reason is - REALITY - it's nearly always the electrolytic or paper capacitors (take it from someone who has been repairing electronics for over 40 years, around 25,000 devices repaired.)

[@petesapwell]

Absolutely sick to death of hearing that rubbish.

[@petesapwell]

@@carlosedwardosso the Atari Lunar Lander PCB I repaired earlier today required a capacitor…No that’s twaddle it needed a 74LS251 multiplexer as non of the switch inputs worked, you are clearly no tech peddling this rubbish… Wondering if you can block idiots on You Tube?

[@lrdisco2005]

Magic smoke escapes.

[@tangothecat237]

Capacitors? I find common failures . Big question mark there.

[@layton7430]

I had a kenwood series 21 amplifier that failed, I searched the Internet, forums the lot and could not find anyone that knew anyone that repaired electronics! I find it sad, we're losing skills so fast.

[@williejcullen]

who the fook is luke and why are you lukeing at him 😁 😂