Board Repair Basics #9 - Diagnosing without schematics

[@Wingedmechanic]

P stands for Power. D stands for data, S for signal. Wherever the component references start with a P - like PR03 or PF01, it most probable refers to a power resistor or fuse.

[@vinodTechHP]

Any good tutorial in Hindi

[@AdaptiveAudio]

What about U as in U24 on the pcb? Im looking at a digitech gnx3 that is not outputting audio and also not able to get past recalibrating the expression pedal. Im assuming its some kind of resistor but it doesnt actually contact the pedal board. It appears to work by detecting the distance between itsself and a metal rod that sits above it. Ive never seen one like this before though.

[@AdaptiveAudio]

Nevermind i found it. Something called a reflective intteruptor.

[@Wingedmechanic]

@@AdaptiveAudio U stands for integrated circuit (IC).

[@AdaptiveAudio]

@@Wingedmechanic thank you. Im still sorta confused on how i should check if its working. Its got 6 pins and the schematic i found labels it as ic sfh9201 reflective interrupter sms06 i cannot find much about anything about testing it online. Just some websites selling them.

[@GMinfoTech-cf8gf]

the best teacher for Computer Technician and electrical engineering.

[@dfn03]

Except all the things he is teaching us aren't always right. Like when he told us we can charge multi-cell(series connected) lipo batteries without a balance charger which is a big NO NO.

[@lockecole6463]

@@dfn03 you can sir even without bms as long as the Volt Difference of cells is near to 0.3v

[@dfn03]

@@lockecole6463 But internal differences between cells can easily put them out of balance of each other. Generally it is a bad idea to charge them without at least monitoring the voltages constantly.

[@ghostmode8665]

@@dfn03 6

[@I_SuperHiro_I]

I am a field engineer who works on IR, Thermal-conductivity, and Thermogravimetric analyzers with resistance furnaces, electrode furnaces, induction furnaces, etc. I encounter pcb issues all the time, but I wasn’t formally trained as an electrical engineer. These are quite helpful. Thank you.

[@MrTrevorroe]

Great, I fix a fair few pcb boards, I thought I would watch this video to see what's going on, well I learned two great tests, just shows 30 years on you don't know everything, ever day is a school day, your a natural teacher with no nonsense, great job thank you 😀 if your learning electronics then stay with this guy, you will learn more in one video than you would in 12 months at college trust me, he is a one off guy who can explain without pulling your hair out, top job 👍

[@carlosgarciaoropeza5480]

I'm slow reacting. I just discovered this section... This first lesson I see is sublime, which makes me admire you even more. I promise to see them all. Thank you very much young Graham for your effort, your dedication and mainly for your time and sharing your knowledge with us (repair audio car stereos / video TV). Sincerely grateful. A fraternal embrace from Mexico.

[@alexogrady3576]

Best instructables on YT for a beginner! Cheers mate so happy to have found your channel!

[@BigEightiesNewWave]

He is a rare find , so good no hype-thumbnails.

[@ashleyharflett4238]

Thanks, being an electrician,who done a TV maintenance course and a Computer repair course (some 15 to 20 years ago) it great to learn a lot more about computers. Keep up the fine work.

[@kelvinkatongo1430]

My first ever repair tutorials.i can't thank you enough man

[@eniac22]

Excellent video series, you are the first that you explain the fault's and the solutions so simply!!! Thanks!!!

[@speed_rider362]

Awesome instructions. I was able to learn a lot from this video. At 5:50 you started talking about letters describing the fuses, capacitors, etc. I'd like to add that P before F, C and what not means "pico", which in turn means something very small.

[@flat-earther]

Thanks for your insight. BTW Pavel I suggest watch a 13 part series called _What on earth happened_ by Ewaranon to learn that the earth is not a globe. I got it in my about tab.

[@Raptors19tdot]

He is one of the best channel for hardware repair. And damn to do it without schematic is master level

[@RobCLynch]

Really good video for generalised theory and learning. It helps to build up knowledge in layers. Very interesting.

[@chavsi8173]

This is also a great video I havev watched so many times, the base for a proper diagnose procedure

[@HCIbn]

I just watched this whole video without falling asleep or maybe I’m just a tech geek for this stuff.

[@manaharlotia7233]

Excellent way of making understand about mother board. short n sweet Demonstration with excellent clarity in voice. thanks for such a nice video.

[@NikholasHolland]

This video is just ridiculous! No way you can be more didactic than this. Incredibly well done job with the analysis on the other video and with the explanation here, including the editing by the way.

[@solosailorsv8065]

Brain Pain; word usage of "ridiculous" is quite negative, yet "didactic" is perfectly employed indicating an intentional misuse of the later. Then the popularly abused "incredible", which has a meaning of "not credible" in many interpretations. The grammar is Dancing !!

[@flat-earther]

@@solosailorsv8065 Sailor I suggest watch a 13 part series called _What on earth happened_ by Ewaranon to learn that the earth is not a globe. I got it in my about tab.

[@KrotowX]

Not always fault happen due to short circuit. Once repaired a laptop where friend's daughter poured a cup of lemon tea with milk over keyboard by accident. Laptop didn't switched on anymore. Sometimes it managed to display BIOS screen and then fell back to darkness. Cleaned a lot of milk gunk from motherboard, then found missing +5V in all motherboard. After thorough search under microscope found two tiny traces with corroded resistor between them. Turned out it was a part of main +5V gate which didn't switched on when resistor was disconnected. Found that it was 200 kOm SMD resistor, replaced it and laptop went back to life. It still works just fine. Interesting that keyboard survived and works still at today without sticky keys.

[@BEOGRADNAVODI]

The best channel for beginners.

[@MasterJediSean]

Very good job on your explanation and the video graphic of the circuit pathways explaining how to trace a circuit. In fact you are doing a excellent job on your other videos. I find your logic to be right on. Cheers from BC!

[@yannd5855]

Thank you very much for your dedication for teaching in such a very good, simple and structured way, I learned a lot

[@fernandogonzalez-qh1kp]

ok my friend but that is only in case some capacitor is damaged, on the other hand we have endless failures related to resistors or signals that enter or leave the south bridge, pch, super io etc etc, greeting from Saltillo Mexico

[@rexford9019]

Have a Kiprim DC310S bench top dc power supply, made in China, which got pulsed with back emf while delivering power to a dc motor. Unit adjusts and delivers power fine but fails to read and/or display amperage. Voltage is also incorrectly displayed at 2 volts less than set voltage. Was able to enter calibration mode following a Russian KZbin video, but does not calibrate. No schematic available. Some component(s) is burnt but cannot locate. Any suggestions?

[@spy6924]

best channel ever for beginners

[@kychemclass5850]

Thank you for helping me boost my electronics knowledge.

[@victorreppeto7050]

repair without a schematic! Thank you sooooooo much!!!

[@crashprovideo7927]

Excellent video sir. Do you only repair PC's or any type of board, out of anything? I have a main power PCB out of a vintage Robot that needs repair and no schematics. Might you be able to take a look? Where is your shop? What do you charge for your repairs? Would really like to have it fixed.

[@deent5186]

Love this video! Thank you so much and I have learned from this video and can fix without schematic

[@Swenser]

Hope you get to post some faults that are more to do with signalling faults rather than power supply shorts. Its harder to know if its a chipset, sio chip or other chip error even if a schematic is referred to. You explain well. Thanx.

[@ichangedmyusername1553]

Why is there one thumbs down? I guess we need to connect two wires to him/her and run some current . You know, to find where the problem is ;-)

[@tythagoras5787]

The manufacturers that want you to buy another instead of repairing.

[@emekaobi2727]

What could be the problem of a system that turns on only after the battery is removed and left for three days it then works for one day and when you shut down it acts as though it wants to come on but it will shut itself down. It will only come up if I repeat the above process again .

[@robinsattahip2376]

I've read the EU is about to mandate schematic and parts availability. Hope they do.

[@johaymarchand-b3909]

Hey man, got an interogstion, working on a ideapad 3 15, I resoled the short on the board (1 capacitor, and 1 burnt mosfet) but now the laptop only blink white at power Led(non-stop) and cpu heating very fast, not able to find any other short Cpu issue🤔😅

[@phpteacher]

so I have a p52 , and I decided to give it a go after following your seeries I found the issue . I know what chip I need to replace . I contacted the maker of the chip and no response . Can you maybe help me out with a lik to where you buy your chips and stuff

[@mahasaravana1169]

I've one PCBA in hand. Whenever I tried to power up the fuse is always blew. Could you help me to figure out the problem ?

[@elviscaragea4433]

Very informative video, 12min of full information

[@flat-earther]

Hi Adamant can you help me through video call repair my laptop with no backlight?

[@A1PhoneAndTech]

Really appreciate your videos! Ive been able to learn A lot from your content!

[@PapaGleb]

Where can I get schematics? I am trying to fix a landline phone which won’t power on and I can’t find any of the traces so I have no idea where is goes after the batteries.

[@theforthdoctor7872]

Outstanding, Louis Rossman without the home-spun philosophy.

[@faustsmith]

What is meant by the term live boot ok concerning a laptop advertisement?

[@Martin-ot7xj]

Hi there , it was one of your perfect and informative tutorial video, especially you typed with red color on the screen .It was very simple and understandable. kindly upload more like this video repair without schematics for beginners.thnx

[@yummyklown9226]

I never wear one. But I do ground myself by touching something that is grounded. (like a frame inside a computer case, or the housing of a power supply. etc. )

[@johnsmith-tr3dh]

Ive watched many many videos of "electronic repair school" channel. He's in Grays UK. Sorin hardly ever uses a schematic. Ive seen him use one for a Macbook Pro, of course.

[@NEQUIZ]

Thank you very much for your video, you explain perfectly for someone who lacks knowledge in electronics. Greetings from Mexico City

[@mohammadbehjat-oz7od]

Hi, would you give me the list of usable capacitor to laptop repair ?

[@renegrunwald2937]

Hey, what if you don't have any schematic and no labeling on the Board? How can I find the point of power IN and OUT of a board if there is no power connection on it?

[@thingshappen9199]

Amazing! First video from you and i automatically subscribed.

[@margyjr]

Great Video, you have inspired me to go back to my Samsung laptop that has a short to grd on the 19v rail! Thanks

[@gersoncastillo2074]

Instead of using schematics and a multimeter, power supply, etc...Isn't it easier to find faults with an IR camera??, or does it only works in some cases??

[@Adamant_IT]

Thermal Cam is a useful tool, but you still need to be able to look at, and understand, board layout. Blindly replacing components that are getting hot isn't always the answer. Video #410 is a really good example of this. Hot component was nothing to do with the fault.

[@A3Piet]

Only led burns, no post. I measure 3.3v at input ‘ON’ button with respect to ground. When I push the ‘ON’ button the voltage drops to zero. Does that mean my 3,3v circuit after ‘ON’ button is shorted?

[@Martin-ot7xj]

please upload more like this video ( Diagnosing without schematics) for beginner

[@smocasa1118]

Save the writing to ask for information, I explain: I recently bought a computer that they had assured me was working and instead they deceived me, the computer does not work. I was wondering could the motherboard be repaired? Why doesn't it turn on. It is a hp

[@isurujaylive]

best IT teacher.

[@ManuEF]

Great work! Very good explained. Thanks a lot.

[@essalaye6695]

How do i know the model of the capacitor to change it. I have a bad capacitor that needed to be replace but don't know the type

[@dandemir5893]

Super helpful video. Thank you sharing all education videos… you are best teacher…

[@andreilucian10]

I have a Lenovo that don`t turn on, i found it some bad fuses and remove them, but are the resistors near those removed fuses who are getting very hot....there is still a short?

[@Adamant_IT]

Use a multimeter to check the resistance to ground. A short circuit is going to be less than 1Ohm between the component and a ground pad. Lots of capacitors and resistors connect to ground on one side, but shouldn't have ground on _both_ sides.

[@andreilucian10]

@@Adamant_IT, thanks a lot for taking from your free time to reply, i.ll do that after i buy a multimeter.Thanks again for replying and for the videos!

[@hatesomeone2220]

Sir, please make video about the differenc between inductor and coil.

[@Adamant_IT]

Same thing. Inductor, Coil, Choke are all the same type of component. They get called different things depending on their role in the circuit, but technically there's no difference.

[@biomed2341]

Does the signal injection also apply in through hole electronic components? if not, do you know a video or link that uses this technique in through hole components on a PCB?

[@vics_media]

Sincere thanks for sharing your very practical knowledge.

[@priekabos22]

best video for reaper !!!! thanks for sharing

[@CornishCarper]

Question: if I have to replace a ROM if all the information matches the top do they have to be reprogrammed?

[@Adamant_IT]

Yes they do. This can be easy or hard depending on the make/model. Most Lenovo BIOS files are available on their website, but need a little conversion work before you can flash them directly to a ROM.

[@poopik3151]

'funny thing i work at a lab fixing cellphones and computers soldering and replacing components and more stuff i didnt finish school and never did any courses i cant sit in class more then 5 minutes losing my patience only hearing this guy standing and talking non stop but siting home blasting my speakers with music while watching this type of vids made me vary good at this

[@onetwo6806]

ADHD

[@poopik3151]

@@onetwo6806 basically yep 😏

[@nenyighunney2207]

Amazing video series. Wanted to ask, is the knowledge here 'transferable' to fixing phone motherboards?

[@segovia102]

This is amazing content pitched at a perfect level for someone who wants to do practical repairs without a huge amount of theory. Does this kind of analysis and fault finding translate to fault finding in, for example, a modern washing machine's main board? I'm dismayed by the fact that if something goes on the blink nowadays it just gets chucked out because supposedly it's cheaper to buy a new one. I have an old iPod lying around that I can't sync to anymore, my brother threw a TV out that had sound but no picture, I recently replaced an LED spotlight that was probably less than two years old because the LED driver failed but the LED die was still fine. It all seems incredibly wasteful. I'd love to see you fault finding in SMPS, linear power supplies, LED drivers, etc. A lot of the content you can find on this stuff is either way too specific (it's only useful to that specific item with that specific fault) and doesn't really cover what can go wrong in a more general sense and how to find it. Either that, or there's way too much theory and they only explain how the thing works but not how to diagnose and repair faults. Anyway, brilliant content, cheers!

I'm just trying to push my casual tech support/reinstalling/ssd swaps/lcd swaps/building/outsourcing small business kinda higher and man, DO A UDEMY COURSES, and i will happilly pay for them. Seriously.

[@laksidecomputers6531]

I love your Chanel. I am happy I found your channel. You make a beginner understand board repair easily. Please give more update sir. Thanks so much

[@qzorn4440]

this is just the type of information needed to work on things like huge John Deere farm equipment, tesla cars, and a world of other computer things. 😎 thanks. 🤩

[@impactodelsurenterprise2440]

Are servo amplifier circuit board more complicated than pc motherboard?

[@aliyuibrahimadamu5106]

Please sir, do you have videos on other electronics?

[@acostin4004]

How long does it roughly take to diagnose mobo fault and what equipment does one need.

[@satriorudi3742]

After seeing this I really helpful with this video

[@hotasfireph]

Hi, I like the way you diagnose motherboard. But do you have any idea, what could be the problem wherein the charger is not recognized, but the charger is working fine? Also, it's not charging for dell laptops.

[@Adamant_IT]

Usually a bad DC jack, the centre pin on a Dell is the sense-pin, and a worn DC jack won't contact it, so the laptop can't read the charger type.

[@onlyeyeno]

Thanks for making these videos and sharing Your knowledge. Best regards

[@aliyuibrahimadamu5106]

Sir, your videos are very helpful and informative

[@joetomperry]

very informative and I really enjoy your channel

[@seamuslily]

where would I get that magnifier/light you are using and what is it called.

[@gideonpetraa1854]

Thanks for dis video very informative.... I an HP probook 645 G1 that comes on when I plug in d charger or battery but d screen is black and d fan is on with full speed plz can u help me out

[@extrememod_ahu]

great video, thank you! can I ask whether say a 17R inductor can be deliberately shorted to ground and not be indication of an issue? I'm trying to fix a motherboard of a Samsung smart TV and I have 4 of these inductors in total on the board (all measure 2-3 Ohms) and 2 of them are shorted and so are several C components around them. Thanks

[@Adamant_IT]

Check what they're powering. 2-3ohms sounds like it's going to a low-impedance CPU or microcontroller. Low-impedance chips will appear to be shorted to ground, but it's quite normal.

[@maxwarfield6699]

PF = protection fuse PL = protection inductor No?

[@lord735]

Hey man i want to know what is the number of my broken ic … how can you help me its Alienware alpha r2

[@bipulkalita5780]

What if the CPU is hot when plugged in the charger, without turning on. And all capacitors near the cpu are shorted.

[@tanerriffat7963]

@Adamant IT Just subscribed to your brilliant channel! Could you share your thoughts on whether repairing boards is a good way to learn and understand PCB design?

[@Adamant_IT]

Cheers! I think it helps - the best way to learn things is when they apply to something you're already interested in. My long-term goals for this channel are to show my subscribers who like the custom PC content how those things work, so they understand the things they like better. However, laptop mobos are a heavy place to start with PCB design. I would highly recommend watching Big Clive - he buys cheap chinese electronics, takes them apart, and explains how the circuits work. Very, very good place to learn electronics. However, hopefully you can pick up a thing or two from my videos too :)

[@tanerriffat7963]

@@Adamant_IT Thanks for the tips. Yes I will watch Big Clive too. Your videos are absolutely fantastic. You have a way of getting straight to the point and a natural flow from one problem to the next. Of course I will watch all of your videos, every single one of them. I like repairing PCB's too but not at your skill level yet. Keep up the great work and thank you so much for sharing your work, you have another avid fan here :)

[@williamlogan4049]

@@Adamant_IT Also Electronics REPAIR School,Sorin there is also very informative like you, however thank you, a new subscriber to your excellent channell

[@kevsmith5363]

Yes very Good at getting a point across you would make a Good mentor

[@SCTCH]

Hello I am curious, how did you know that this is an Inductor opposed to resistor ?

[@johnny_9633]

How to find the value of dead capacitor without schematics?

[@Martin-ot7xj]

hi there, please make a tutorial video about how to diagnose short to the ground and how we can resolve the problem !! thnx

[@nattan3226]

hello is there any chance you can switch the video board repair basics #10 from private to public? if so id really appreciate a lot.

[@flat-earther]

NAT TAN I suggest watch a 13 part series called _What on earth happened_ by Ewaranon to learn that the earth is not a globe. I got it in my about tab.

[@EvgeniX.]

a question: if you have to replace a capacitor, without schematic, how do you know the value required?

[@Sorest2]

After watching a lot of his videos, the way he does it is usually by measuring capcitors that look similar (as they likely have the same purpose) in the nearby area close to the one being replaced.

[@electrance9282]

That's an excellent job my friend 9.8/10

[@andywarwick3745]

Would you be interested in a private job for high quantity of Satalite boxes?

[@floridahummer]

you should be teaching kids how to do this, fantastic vidoes

[@redfrog2100]

I was looking for such theory.. Keep the macro way..thanks

[@armanjosephmarasigan8324]

Thank you

[@PapaGleb]

Glad I ran across your channel. Just started learning electronics and repair. I’m currently figuring out how serious static charge is. I see many video including your where people aren’t grounded or at least I can’t see that they are. Do I really need a grounding strap?

[@CB27]

I think he's using an anti-static mat. Basically it's grounded. I remember seeing internal photos of semiconductor devices taken with a microscope after they'd been zapped by electrostatic discharge. They were pitted like they'd been hit by lightning. Which is basically what ESD is on a smaller scale. The results for the affected IC are either intermittent faults (very hard to troubleshoot and isolate) or catastrophic failure. For the sake of wearing something simple as a ground strap or use a ESP mat, it's just not worth the risk. Look up any HP service manual, it lists the electro static charges that can build up under various scenarios like walking across the floor or simply working at a workstation.

[@andrescarrasco1248]

Would you ever try repairing a PS4 or switch mb with this method? As the little pieces are a bit more available to buy than any laptop

[@Adamant_IT]

Closest I've done to that is looking at an Xbox One, which I found was missing it's 3.3v rail. But given the second hand cost of an Xbone (non-x) it wasn't worth seeing the repair through. Theoretically though, they're a lot like laptops, and can be fixed in the same way.

[@iramgo]

is ther any video about surface pro 4 pcb ,

[@moss991972]

Fantastic series , thanks , are desktop motherboards similar to diagnose ?

[@Adamant_IT]

I've never attempted board repair on a desktop mobo... They differ in that there's a lot less power-related stuff going on (secondary rails are all in the PSU, it's just CPU and RAM power on the mobo) and a great deal more data busses for PCI-E and such. I might take a swing at it some time if a failed board comes up, but I wouldn't fancy my chances. Laptops tend to suffer more basic problems that are easier to find.

[@dylanjones678]

3:10 Capacitor absorbing voltage spike from inductors collapsing magnetic field when circuit opens?

[@Martin-ot7xj]

Hi there, your tutorial video was very useful and informative. Keep it up. Thnx

[@MrPnew1]

Well explained, thanks. So glad that Macbook stuff has "come our way" though :) plus Macbook repair is where the money is

[@joeybi3504]

Hi, do you have a video regarding in Lenovo yoga 2 pro blank screen. Power On, lights on laptop and keyboard and you can hear fan spin. But screen is blank. How to troubleshoot this issue.

[@MrPnew1]

@@joeybi3504 you might be better directing your query to Adamant IT

[@DarkoPetreski]

@@joeybi3504 Check the display cable.

[@springer-qb4dv]

True, but for hobbyists and DIY repairs, PC laptops are much better.