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.
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.
@@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.
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 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.
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.
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.
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 👍
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.
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.
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 !!
@@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.
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.
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.
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?
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.
@@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!
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!
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.
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
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.
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 .
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 TH-cam video, but does not calibrate. No schematic available. Some component(s) is burnt but cannot locate. Any suggestions?
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
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
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🤔😅
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.
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??
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.
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?
The naming conventions of components on laptop motherboards, as shown in the image, typically follow standardized or manufacturer-specific identifiers. These labels help technicians and engineers identify and troubleshoot specific components or sections of the circuit. Here’s a breakdown of what the naming conventions signify: --- ### **1. Prefixes Indicating Component Type** The letters preceding the numbers indicate the type of electronic component or function of the part. Common conventions include: | **Prefix** | **Component Type** | **Examples from Image** | |------------|-------------------------------------------|--------------------------| | **L** | Inductors (chokes, coils) | L5, L12 | | **R** | Resistors | R1, R32 | | **C** | Capacitors | Not labeled here but common (e.g., C1) | | **F** | Fuses | F1 | | **Q** | Transistors (MOSFETs, BJTs) | Q22, Q4 | | **D** | Diodes | D13, D20 | | **U** | Integrated Circuits (ICs) or Chips | U8, U61 | | **P** | Connectors, Ports, or Jumpers | PJ301 | | **J** | Jumpers, Headers, or Connectors | J12 | | **T** | Transformers | None visible here | | **FL** | Ferrite Beads or Inductor-like Filters | FL101, FL102 | These prefixes are typically followed by numbers to uniquely identify the specific component. --- ### **2. Numbering System** - The numbers after the prefix (e.g., `R32`, `L12`, or `FL101`) are unique identifiers for the specific component on the PCB. - In most cases, numbering starts from 1 in a particular category (e.g., resistors may start with R1, R2, etc.) and may increment based on their placement in the circuit. --- ### **3. Example Analysis from the Image** #### **FL101, FL102** - **FL** refers to ferrite beads or filtering components. - These are typically used to suppress high-frequency noise in power lines or data lines. #### **F1** - **F** stands for a fuse, used to protect circuits from overcurrent conditions. - This ensures safety by breaking the circuit when current exceeds safe levels. #### **Q22** - **Q** refers to a transistor, likely a MOSFET here, as is common in power management circuits on motherboards. - Used for switching or power regulation tasks. #### **U8, U61** - **U** denotes integrated circuits (ICs), such as controllers, voltage regulators, or logic gates. - The numbers identify individual ICs in the design. #### **L12** - **L** refers to an inductor, used for filtering or energy storage in switching regulators. #### **JUSB** - **J** typically refers to connectors or headers. Here, **JUSB** likely refers to the USB connector for power or data. #### **D13, D20** - **D** refers to diodes, used for rectification, clamping, or protection against reverse voltage. --- ### **4. Manufacturer-Specific Variations** While these prefixes are widely adopted, some manufacturers may use slightly different conventions. These can vary depending on: - The manufacturer (e.g., Dell, Lenovo, HP, etc.). - The specific design standards or documentation practices of the engineering team. --- ### **5. Debugging or Repair Use** These naming conventions are essential for: 1. **Circuit Diagnosis:** - Helps identify faulty components during troubleshooting. 2. **Referencing Schematics:** - Matches the names on the PCB with schematic diagrams for clarity. 3. **Replacement or Repair:** - Knowing the type of component simplifies sourcing replacements. --- ### **6. Common Areas of Laptop Motherboards** - **Power Management (e.g., FL, Q, U components):** - Ferrite beads (FL), transistors (Q), and ICs (U) are clustered near power input ports or regulators. - **Data Lines (e.g., JUSB, D components):** - Connectors (J) and protection diodes (D) are located near data ports like USB. - **Filter and Protection Components (e.g., F, L components):** - Inductors (L), ferrite beads (FL), and fuses (F) are used to ensure clean power delivery and safety. Understanding these conventions makes it much easier to pinpoint faults and replace damaged components. If you have specific questions about one component or its role in the circuit, feel free to ask!
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. 🤩
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.
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.
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?
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.
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
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. )
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.
'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
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
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.
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!
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.
Early in the video, you say, more or less, that “ ...a section of the board isn’t getting power, so it’s probably a short circuit...”. I’m a novice but I would think that, if a section isn’t getting power, it probably means that there is an opened component - not a short. How are you so confident that it is, a short - what makes you think that and not, an open discrete component? Please let me know, I’m trying to learn. Thank you kindly
On motherboards, there's not a lot of components that are likely to fail-open. Usually it's capacitors that fail-closed. This either drags the rail down to 0v, or the next power supply up the chain will detect over-current and switch off the shorted section.
hi brother thank for all I have lenovo u330 Core2 duo old model there is no back light on display i can see 3.3 volt I coudnt see 19 volt and I have no shematic . it was working I forget to take out power and pluged lcd flex after happend can you help me for that please
I REALLY need your help sir.. My laptop stopped turning on (it doesnt do anything) and i removed the back cover and when i did a 1mm silver colored dimmy fell out of the motherboard.. It is a fuse i believe ?? Im not sure but it is located right next to the battery connecting wire.. This PC is crucial to me and i will try to get in contact with you via your website. In Denmark where i am i have been searching far and wide for a shop that could do this kind of soldering repair but they are all just not willing to do it and/or not capable of :( . The laptop is only 6 months old and i have no idea how it actually happened that this fuse or whatever it is came lose just like that. I will try to give you a call tommorow and see if you would help
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.
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?
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?
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.
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.
@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?
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 :)
@@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 :)
@@Adamant_IT Also Electronics REPAIR School,Sorin there is also very informative like you, however thank you, a new subscriber to your excellent channell
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.
Any good tutorial in Hindi
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.
Nevermind i found it. Something called a reflective intteruptor.
@@AdaptiveAudio U stands for integrated circuit (IC).
@@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.
the best teacher for Computer Technician and electrical engineering.
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.
@@dfn03 you can sir even without bms as long as the Volt Difference of cells is near to 0.3v
@@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.
@@dfn03 6
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.
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.
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 👍
Best instructables on YT for a beginner! Cheers mate so happy to have found your channel!
My first ever repair tutorials.i can't thank you enough man
He is a rare find , so good no hype-thumbnails.
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.
Excellent video series, you are the first that you explain the fault's and the solutions so simply!!! Thanks!!!
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.
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 !!
@@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.
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.
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.
He is one of the best channel for hardware repair. And damn to do it without schematic is master level
Really good video for generalised theory and learning. It helps to build up knowledge in layers.
Very interesting.
This is also a great video I havev watched so many times, the base for a proper diagnose procedure
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?
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.
@@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!
best channel ever for beginners
I just watched this whole video without falling asleep or maybe I’m just a tech geek for this stuff.
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!
Excellent way of making understand about mother board. short n sweet Demonstration with excellent clarity in voice. thanks for such a nice video.
The best channel for beginners.
repair without a schematic! Thank you sooooooo much!!!
Hi Adamant can you help me through video call repair my laptop with no backlight?
Very informative video, 12min of full information
Sir, please make video about the differenc between inductor and coil.
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.
Thank you for helping me boost my electronics knowledge.
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
Amazing! First video from you and i automatically subscribed.
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.
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 .
best IT teacher.
Thank you very much for your dedication for teaching in such a very good, simple and structured way, I learned a lot
I've read the EU is about to mandate schematic and parts availability. Hope they do.
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 TH-cam video, but does not calibrate. No schematic available. Some component(s) is burnt but cannot locate. Any suggestions?
Really appreciate your videos! Ive been able to learn A lot from your content!
best video for reaper !!!! thanks for sharing
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
Love this video! Thank you so much and I have learned from this video and can fix without schematic
Great work! Very good explained. Thanks a lot.
Thank you so much for these videos!
3:10 Capacitor absorbing voltage spike from inductors collapsing magnetic field when circuit opens?
That's an excellent job my friend 9.8/10
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
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🤔😅
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.
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??
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.
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 ?
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?
The naming conventions of components on laptop motherboards, as shown in the image, typically follow standardized or manufacturer-specific identifiers. These labels help technicians and engineers identify and troubleshoot specific components or sections of the circuit. Here’s a breakdown of what the naming conventions signify:
---
### **1. Prefixes Indicating Component Type**
The letters preceding the numbers indicate the type of electronic component or function of the part. Common conventions include:
| **Prefix** | **Component Type** | **Examples from Image** |
|------------|-------------------------------------------|--------------------------|
| **L** | Inductors (chokes, coils) | L5, L12 |
| **R** | Resistors | R1, R32 |
| **C** | Capacitors | Not labeled here but common (e.g., C1) |
| **F** | Fuses | F1 |
| **Q** | Transistors (MOSFETs, BJTs) | Q22, Q4 |
| **D** | Diodes | D13, D20 |
| **U** | Integrated Circuits (ICs) or Chips | U8, U61 |
| **P** | Connectors, Ports, or Jumpers | PJ301 |
| **J** | Jumpers, Headers, or Connectors | J12 |
| **T** | Transformers | None visible here |
| **FL** | Ferrite Beads or Inductor-like Filters | FL101, FL102 |
These prefixes are typically followed by numbers to uniquely identify the specific component.
---
### **2. Numbering System**
- The numbers after the prefix (e.g., `R32`, `L12`, or `FL101`) are unique identifiers for the specific component on the PCB.
- In most cases, numbering starts from 1 in a particular category (e.g., resistors may start with R1, R2, etc.) and may increment based on their placement in the circuit.
---
### **3. Example Analysis from the Image**
#### **FL101, FL102**
- **FL** refers to ferrite beads or filtering components.
- These are typically used to suppress high-frequency noise in power lines or data lines.
#### **F1**
- **F** stands for a fuse, used to protect circuits from overcurrent conditions.
- This ensures safety by breaking the circuit when current exceeds safe levels.
#### **Q22**
- **Q** refers to a transistor, likely a MOSFET here, as is common in power management circuits on motherboards.
- Used for switching or power regulation tasks.
#### **U8, U61**
- **U** denotes integrated circuits (ICs), such as controllers, voltage regulators, or logic gates.
- The numbers identify individual ICs in the design.
#### **L12**
- **L** refers to an inductor, used for filtering or energy storage in switching regulators.
#### **JUSB**
- **J** typically refers to connectors or headers. Here, **JUSB** likely refers to the USB connector for power or data.
#### **D13, D20**
- **D** refers to diodes, used for rectification, clamping, or protection against reverse voltage.
---
### **4. Manufacturer-Specific Variations**
While these prefixes are widely adopted, some manufacturers may use slightly different conventions. These can vary depending on:
- The manufacturer (e.g., Dell, Lenovo, HP, etc.).
- The specific design standards or documentation practices of the engineering team.
---
### **5. Debugging or Repair Use**
These naming conventions are essential for:
1. **Circuit Diagnosis:**
- Helps identify faulty components during troubleshooting.
2. **Referencing Schematics:**
- Matches the names on the PCB with schematic diagrams for clarity.
3. **Replacement or Repair:**
- Knowing the type of component simplifies sourcing replacements.
---
### **6. Common Areas of Laptop Motherboards**
- **Power Management (e.g., FL, Q, U components):**
- Ferrite beads (FL), transistors (Q), and ICs (U) are clustered near power input ports or regulators.
- **Data Lines (e.g., JUSB, D components):**
- Connectors (J) and protection diodes (D) are located near data ports like USB.
- **Filter and Protection Components (e.g., F, L components):**
- Inductors (L), ferrite beads (FL), and fuses (F) are used to ensure clean power delivery and safety.
Understanding these conventions makes it much easier to pinpoint faults and replace damaged components. If you have specific questions about one component or its role in the circuit, feel free to ask!
Thank you very much for your video, you explain perfectly for someone who lacks knowledge in electronics. Greetings from Mexico City
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
What is meant by the term live boot ok concerning a laptop advertisement?
Hi, would you give me the list of usable capacitor to laptop repair ?
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. 🤩
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.
Sincere thanks for sharing your very practical knowledge.
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.
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?
Please sir, do you have videos on other electronics?
Super helpful video. Thank you sharing all education videos… you are best teacher…
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.
hi there, please make a tutorial video about how to diagnose short to the ground and how we can resolve the problem !! thnx
Great Video, you have inspired me to go back to my Samsung laptop that has a short to grd on the 19v rail! Thanks
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 ;-)
The manufacturers that want you to buy another instead of repairing.
is ther any video about surface pro 4 pcb ,
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
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. )
Question: if I have to replace a ROM if all the information matches the top do they have to be reprogrammed?
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.
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
Are servo amplifier circuit board more complicated than pc motherboard?
Excellent video!
After seeing this I really helpful with this video
'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
ADHD
@@onetwo6806 basically yep 😏
Hey man i want to know what is the number of my broken ic … how can you help me its Alienware alpha r2
Yes very Good at getting a point across you would make a Good mentor
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
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.
please upload more like this video ( Diagnosing without schematics) for beginner
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!
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.
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.
Hello sir nice work ,please do you have any videos on how to trace a dead phone .thanks
I'm a total novice with phones I'm afraid. I don't think they can be traced, they're too densely packed.
Sir, your videos are very helpful and informative
How long does it roughly take to diagnose mobo fault and what equipment does one need.
Thanks for making these videos and sharing Your knowledge.
Best regards
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.
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.
Early in the video, you say, more or less, that “ ...a section of the board isn’t getting power, so it’s probably a short circuit...”. I’m a novice but I would think that, if a section isn’t getting power, it probably means that there is an opened component - not a short. How are you so confident that it is, a short - what makes you think that and not, an open discrete component? Please let me know, I’m trying to learn. Thank you kindly
On motherboards, there's not a lot of components that are likely to fail-open. Usually it's capacitors that fail-closed. This either drags the rail down to 0v, or the next power supply up the chain will detect over-current and switch off the shorted section.
@@Adamant_IT Thank you, sir. Be safe
hi brother thank for all
I have lenovo u330 Core2 duo old model there is no back light on display i can see 3.3 volt I coudnt see 19 volt and I have no shematic . it was working I forget to take out power and pluged lcd flex after happend can you help me for that please
How to find the value of dead capacitor without schematics?
very informative and I really enjoy your channel
I REALLY need your help sir.. My laptop stopped turning on (it doesnt do anything) and i removed the back cover and when i did a 1mm silver colored dimmy fell out of the motherboard.. It is a fuse i believe ?? Im not sure but it is located right next to the battery connecting wire.. This PC is crucial to me and i will try to get in contact with you via your website. In Denmark where i am i have been searching far and wide for a shop that could do this kind of soldering repair but they are all just not willing to do it and/or not capable of :( . The laptop is only 6 months old and i have no idea how it actually happened that this fuse or whatever it is came lose just like that. I will try to give you a call tommorow and see if you would help
Hi, I'm not currently taking on repairs from outside the UK - so I can't help with this one I'm afraid!
@@Adamant_IT awww thats so bad man.. Nobody does it in this country .
@@Adamant_IT If you are willing to do it i will create a whole new website for you with any features you would like. Please re-consider
@@Adamant_IT Booking system , SEO optimized, anything.
What if the CPU is hot when plugged in the charger, without turning on. And all capacitors near the cpu are shorted.
Fantastic series , thanks , are desktop motherboards similar to diagnose ?
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.
where would I get that magnifier/light you are using and what is it called.
thank you Adam!
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?
Looking at the board, would P in the name maybe signify it is part of the power rails/power delivery related?
That sounds sensible, yes 👍
the p could indicate that it is a poly fuse
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?
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.
a question: if you have to replace a capacitor, without schematic, how do you know the value required?
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.
Outstanding, Louis Rossman without the home-spun philosophy.
@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?
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 :)
@@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 :)
@@Adamant_IT Also Electronics REPAIR School,Sorin there is also very informative like you, however thank you, a new subscriber to your excellent channell
Amazing video series. Wanted to ask, is the knowledge here 'transferable' to fixing phone motherboards?
.. God bless sir .. always watching take care 😇🤗