How To Repair Without Schematics? Try This Easy Method

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  • เผยแพร่เมื่อ 25 ธ.ค. 2024

ความคิดเห็น • 81

  • @warwickbunn1250
    @warwickbunn1250 ปีที่แล้ว +18

    I do like this methodical approach to identifying parts of the board first, as it gives me a better chance of understanding what is going on. But I also need to watch it again 😅
    What further tests could you do to confirm your suspicions ?
    Would you inject the correct voltage onto the output leg of the chip to see if it then started to charge the battery ? Or something else ?
    I still love the fact that for a few £s etc you can fix something valuable in money terms and owners pleasure, rather than throw it away.
    Keep them coming Richard 👏

  • @Graham_Wideman
    @Graham_Wideman ปีที่แล้ว +8

    LER: Your process seems good to me. One thing I do for this type of task is to shoot a photo, put that in a drawing software (I happen to use Visio), which gives me an image to either print and write upon, or to annotate in the drawing software. You can reduce the contrast and intensity of the image so that what you write on it (or annotate) stands out better. This is also helpful for 2-layer boards: shoot a picture of each side (try to make the images square to the board). Then in the drawing software we vary the transparency, possibly also modify the color map, to be able to visualize the traces on front an back. This even somewhat works for 4-layer boards, since often on those boards the inner layers and ground and power planes. Anyhow, the basic idea is that using images in conjunction with drawing software really helps, but even just printing out the image (with faded contrast) gives a quick start to a sketch on which to write clues.

    • @dicko-200
      @dicko-200 8 หลายเดือนก่อน +1

      great idea. I have a Mac so I'm going to try it with Pages.

  • @malectric
    @malectric ปีที่แล้ว +1

    I've had to do a lot of blind troubleshooting in my time. Being able to access datasheets for various chips online can be a big help.

  • @harrymartin1661
    @harrymartin1661 ปีที่แล้ว +2

    Very good explanaitons, greatings from Sweden.

  • @andymouse
    @andymouse ปีที่แล้ว +4

    Great tutorial ! this stuff is priceless as people do wonder what the trick is but slowly finding whats actualy on the board IS the trick...cheers.

  • @Yreq
    @Yreq ปีที่แล้ว +1

    This video is really priceless learning to repair suff. With this knowlegde only availbility of datasheets and those bloody smd-codes are the limit.Thanks😃

  • @logothaironsides2942
    @logothaironsides2942 10 หลายเดือนก่อน

    Wow that is very useful. Im a complete newbie as far as understanding the boards. A few times ive been lucky with mending things but now I want to undertsand rather than guess so this is perfect as an intro.

  • @mansjacobsson5823
    @mansjacobsson5823 ปีที่แล้ว +4

    Thanks for another excellent video.
    How come every time I watch you, recognising components and describing what they are, I sit and nod and follow you perfectly. But as soon as I try to repair something, I fail to see the patterns and recognise the parts.😂

    • @LearnElectronicsRepair
      @LearnElectronicsRepair  ปีที่แล้ว +4

      It's just experience, keep going and it will come with time.

    • @andymouse
      @andymouse ปีที่แล้ว +3

      Its like going to the doctors with a full list of questions in your head and when you arrive you have nothing o say :)

    • @rongoodchild3048
      @rongoodchild3048 ปีที่แล้ว +1

      You don't know the theory behind each circuit or component get your hands dirty

  • @elcocineroamericano
    @elcocineroamericano ปีที่แล้ว +4

    This was a great breakdown of the simple and methodical way to work around not knowing much about the equipment on your bench. Both interesting and useful. Thanks!

  • @timflynn3218
    @timflynn3218 ปีที่แล้ว +7

    Love the process you went through. I have a lot of things that don't have schematics, and the method of figuring out what you have in hand is important. Out of curiosity; would an IR image of the charger show you if it is working or not? I imagine it would get warm if it was working and stay at ambient temperature if it isn't working. I don't have an IR camera for that kind of thing, just use my finger to sense it. But yeah, at this point, I would change the chip. Great job Richard!

  • @duncansmith3195
    @duncansmith3195 ปีที่แล้ว +2

    Thank you, what a good video.

  • @surgingcircuits6955
    @surgingcircuits6955 ปีที่แล้ว

    I really liked this approach. Very close to my own. Sensible and logical. Thx.

  • @BoB4jjjjs
    @BoB4jjjjs ปีที่แล้ว +1

    You should do more of this to help people that are starting out in the hobby or new to repairs. I think they would find it very helpful, even those that have repaired electronics as a hobby for a few years would find this very helpful.
    For all the cost of that chip, I would replace it if the input voltages were about right. Otherwise, I would be looking at the supply to the chip. For all the cost of this chip, I would just replace it, however, if it was an expensive chip, I would be checking supply voltages around the chip. EDI|T: Typo

  • @robertorocha937
    @robertorocha937 ปีที่แล้ว +1

    Excellent sir .i going to aplicade im my repairs

  • @Lightrunner.
    @Lightrunner. ปีที่แล้ว +1

    Richard, perfekt combined explaination👍👍👍👍👍👍
    but you have forgott the most Imprtant thing😱😱.
    Where are the coffe and biscuits ?? 😭 Without is no repair possible.

  • @kennyrmurray
    @kennyrmurray ปีที่แล้ว

    Try the chip and make another video when you get it. I think I have watched all of your videos more then once. Great job explaining and teaching people like myself! I’m just a hobbyist getting back into this. What are some of the best sites to get schematics from? I have an Antec SU-380 power supply that’s only putting out 9V at on the 12V wires that I’d like to diagnose. I want to print it out. Maybe somebody can help me? It’s been about 4 years and I can’t remember what sites I used to get my schematics from. Thanks to anybody that can name a few to help me. Keep up the great videos please, I love them and I see a lot of others do too!!

  • @johnfitzpatrick2469
    @johnfitzpatrick2469 ปีที่แล้ว

    G,day from Sydney Australia.
    Thank you for your video on the Bose speakers.
    Learning outcomes
    * magnification and inspection of all PCB tracks, components (swollen caps, missing solder, incomplete circuits).
    * identify components ID numbers and internet search for manufacturers specs.
    * test areas of power supply using omega and continuity.
    🇭🇲💫🔋p.s I did notice that solder is not shining as usual (quiry contacts... yeah.)

  • @klumpy103
    @klumpy103 ปีที่แล้ว

    The guy has obviously invested some time, so i think its worth completing the circle 👍, i do like your methodical approach showing beginners how to approach initial debug. Something you didnt mention ( although not critical in this case ) were the other clues on the board eg. the capacitor voltage ratings. Also ,It's a good feeling to point the finger and have it confirmed.

  • @billcedarheath387
    @billcedarheath387 ปีที่แล้ว +1

    I’m curious if you could do a video on how to remove the blob material from a component that is coated in the stuff. I’ve got a board that I’m trying to sort out an issue on. The problem is I can’t test it with the encapsulated component and I’m afraid of damaging it with trial and error removal.
    If you could do such a video, I’m sure I wouldn’t be the only one grateful to see it.
    I’m really happy you do these videos. Good stuff!

    • @Infiniti25
      @Infiniti25 ปีที่แล้ว

      I’ve been told that most of the time it’s an IC on a crystal, definitely will get damaged removing the blob. Even if you could remove it you can’t replace it in most instances.
      I have someone’s Christmas merry go round musical carousel that has this type of blob crystal IC and I can’t solve this for the 94year old owner unfortunately.

  • @enginewatcher6291
    @enginewatcher6291 ปีที่แล้ว

    For me, i would like to see more use of the pcb test points to generalise the layout/functionality. Right at the end yes i agree charge controller IC is very probable. My next step would be using a bench power supply inject a charging voltage on the IC output and verify the battery voltage increased. This could save time later if you change the IC and the problem did not resolve, you would have a second delay waiting on another shipment of the next test parts, you could order them all at one time, also save on shipping cost.
    Great methodology will be trying this by drawing it out, which is the magic skill bit we do in out head, usually as we reverse engineer to draw a schematic

  • @CliveChamberlain946
    @CliveChamberlain946 ปีที่แล้ว +2

    Sure wish Richard's InfiRay P2 was always attached to a swing boom and connected to his OBS PC. Even though OBS see's it as grey-scale, that's good enough so it can become an active part of the process. I bought a P2 Pro based on Richards review and since IR cams are more economical now, I see it could become almost a "must have" on a lot of benches going forward.🤗

    • @LearnElectronicsRepair
      @LearnElectronicsRepair  ปีที่แล้ว +3

      When I tried the InfiRAY with OBS It was detected as a video source but I could not open a window to view it. That may have been the T2S+, I will ahve to try again with the P2 Pro

    • @CliveChamberlain946
      @CliveChamberlain946 ปีที่แล้ว +2

      @@LearnElectronicsRepair Mine shows up in sources in OBS 30.0 as "Video capture device (V4L2)" on Mint Linux with a 6.2 Kernel (no drivers needed). Camera properties are all default. Love this camera, thanks again for recommending it!🤗

  • @gendragongfly
    @gendragongfly ปีที่แล้ว +1

    I miss one step in this WoW and that is checking if the chip that appears to be misbehaving has a good ground connection. The chip may be receiving 15 volts as an input and 5 volt on the enable pin, but if the ground if floating for some reason, it still may not start.

  • @DrFiero
    @DrFiero ปีที่แล้ว

    @34:40 or thereabouts, you were saying there should be 15V at pin 1 of the FP8207 since that's what the wall wart is puting out. But isn't there a zener just to the left that would cause a drop?

    • @DrFiero
      @DrFiero ปีที่แล้ว

      D6 on the board looks like that one. The max input was only 12.xx or something right? If D6 was shorted, wouldn't it over voltage the chip?

  • @Peter-rt3tu
    @Peter-rt3tu ปีที่แล้ว

    Before replacing the chip I would check for shorts on the output side, defective caps or the like. Maybe there was a reason for it to blow up.

    • @supergeekjay
      @supergeekjay ปีที่แล้ว

      The old battery could have developed an issue, the chip sacrificed itself to prevent a bigger problem?

  • @marcellipovsky8222
    @marcellipovsky8222 ปีที่แล้ว +2

    Hi Richard, just an idiot's comment here - does the chip have a proper ground connection? Are all the chip's connections ok? No bad solder joint? I mean, that speaker system is portable and those things get dropped. It could be as easy as a cracked solder joint.

  • @stellargreg4481
    @stellargreg4481 ปีที่แล้ว

    Great video! Is that a burn mark where the data sheet shows a ground at pin 15? The bottem of the chip as I'm watching the video. IDK but it looks suspicious to me.

  • @markweiss5152
    @markweiss5152 ปีที่แล้ว +1

    The only thing else I would is use the bench power supply to charge the battery some, then reconnect battery. if that did not fix it, change out the chip.

  • @michaelrollins3979
    @michaelrollins3979 ปีที่แล้ว

    Love your videos! Have a question. I’m repairing a multimeter that had too much voltage go through it and after doing some testing I’ve found 2 resistors out of spec and dropping voltage without current flow. I can’t find replacements anywhere 10M .25% and 900k 1% any advice?

  • @cuanhogan4330
    @cuanhogan4330 ปีที่แล้ว

    Hi Richard, greetings from South Africa, can you discuss the operation of the feedback circuit connected to the FB pin of the chip ?. Could this be affecting things ? Thanks once again for sharing your valuable knowledge. Kind regards

  • @tenlittleindians
    @tenlittleindians ปีที่แล้ว

    I know just enough about electronics to follow along like a dog on a leash.
    I've been playing around with lipo batteries just enough to recognize cell pack voltages and your voltages seem correct.
    Most lipo charge circuits rely on a BMS (battery management system) which is often built into the battery pack itself.
    Since he's swapped out the battery pack with a new one I suspect any BMS in the battery pack to be good.
    A guess says two wires to a battery are for power and anything over two are possibly for BMS duty.
    Is this chip on the motherboard the only BMS in this circuit or is there also one in the battery pack itself? What happens if that BMS signal is broken between the battery and the motherboard and how do you check it?

  • @d614gakadoug9
    @d614gakadoug9 ปีที่แล้ว +1

    Why is the charging light flashing? Is that the way it normally behaves? The datasheet for the charge controller only mentions "flash" with regard to the package and doesn't explain the status output well. Does the user manual for the whole system say anything about the charging light? Is the LED being driven directly by the charger IC or something else that gets the status signal from the charger?
    I would check the temperature input from the battery, since an overtemp condition, even if it isn't real, will shut down charging.
    I would use an oscilloscope to see if the charger chip is attempting to do anything at power-up. It may be trying and shutting down for some reason.

    • @filipthedev
      @filipthedev ปีที่แล้ว

      Yes, the LED flashes until it's charged, and once charged, turns solid. Not too sure what it's driven by though.

    • @supergeekjay
      @supergeekjay ปีที่แล้ว

      @@filipthedev It is confusing, as normally they are red for charging, and green or extinguished for charged!

    • @filipthedev
      @filipthedev ปีที่แล้ว

      @@supergeekjay Agreed!

  • @scottfirman
    @scottfirman 11 หลายเดือนก่อน

    I had someone give me one of those. It turned out the issue was in the flexible flat wire tape . It had degraded to the point it was no longer working properly. Being the tape is specific to that unit, there was no possible way to replace it without a donor unit. I have seen this with others, so it is a known issue with this unit. Over time, the tape breaks down and no longer carries electricity. I traced the issue down to this specific thing using several methods. I thought simply cleaning the snap in carriers and ends of the tape would do it, but the unit would only work again for a short time, then fail again. Ultimately, I ended up scrapping it.

  • @Paul-q3f8j
    @Paul-q3f8j ปีที่แล้ว +4

    I'd put a NEW chip in for my own curiosity

  • @Dutch_off_grid_homesteading
    @Dutch_off_grid_homesteading ปีที่แล้ว

    Heya, this is a good way too maybe I can use this with my liitokala 18650 4x cell tester 2 of the 4 don't work anymore and still have to test couple of honderds of them

  • @1984Kojot
    @1984Kojot ปีที่แล้ว

    Was it chip eventually??

    • @LearnElectronicsRepair
      @LearnElectronicsRepair  ปีที่แล้ว +1

      Waiting for parts - then we will find out

    • @Omega3131
      @Omega3131 8 หลายเดือนก่อน

      @@LearnElectronicsRepairAnd... don't keep us in suspense :P

  • @Cb138inRs
    @Cb138inRs ปีที่แล้ว

    Wouldn't it just be possible to short or jump across and attempt to change the chip mode into the charging state. Would prove the ch ip is bad. Possible even negate a need for a new chip, but might have to pay close attention to what you're bypassing

  • @knightwar3
    @knightwar3 ปีที่แล้ว

    I hope the new chip will work for you

  • @htwt
    @htwt ปีที่แล้ว +1

    Why order a new part even though you didn't find out the lack of an EN signal?

    • @LearnElectronicsRepair
      @LearnElectronicsRepair  ปีที่แล้ว +2

      The EN signal *was* present. According to the datasheet the charger chip should start as all the conditions are present, and it doesn't. Unless I misunderstood the datasheet.

    • @htwt
      @htwt ปีที่แล้ว

      @LearnElectronicsRepair 35:50 There was 4.8V on the EN pin. Should be more than 15V. Or the same as HVDD on the pin.

    • @htwt
      @htwt ปีที่แล้ว +4

      Sorry I am tolally wrong. Enable Threshold voltage 1.15 1.2 1.25 V

  • @warunakumara7671
    @warunakumara7671 ปีที่แล้ว

    sir u r not thinking about the smd caps and smd devices whys that , guide us how to read the esr value of smd cap ,

    • @Cb138inRs
      @Cb138inRs ปีที่แล้ว +1

      desolder and check with a Multimeter

    • @andymouse
      @andymouse ปีที่แล้ว

      For the 'ESR' you will need a meter :)

    • @warunakumara7671
      @warunakumara7671 ปีที่แล้ว

      @@Cb138inRs how to find smd ceramic cap values they r not written on it how to test it

  • @Dutch-linux
    @Dutch-linux ปีที่แล้ว

    well there that shipping is just as much as the chip it self it is only worth it if you would buy like 10 of them but yeah for that price it is worth it to just raplace it and see if that would solve the problem if not well it has a fresh new charger chip lol then just have to investigate more

  • @manisteve862
    @manisteve862 ปีที่แล้ว

    Change it !

  • @mopatibogatsu7941
    @mopatibogatsu7941 ปีที่แล้ว

    How do you spell buk converter

  • @SirasPK
    @SirasPK ปีที่แล้ว +4

    i don't like cliffhanger videos.

  • @sarathai2876
    @sarathai2876 ปีที่แล้ว

    I say change the chip

  • @sherlockholmes1121
    @sherlockholmes1121 ปีที่แล้ว

    Amplifier with no heat sink ? looks sus to me !

    • @d614gakadoug9
      @d614gakadoug9 ปีที่แล้ว +4

      It is a class D amplifier - basically a switchmode power converter with duty cycle controlled by an analog signal. They are very efficient and foil on a PCB can be sufficient for heatsinking. There is a "slug" on the back of the package. It solders to the foil on the PCB. The actual IC die is mounted on the other side of the slug. Typically a bunch of vias are used to help conduct heat through the PCB to foil areas on the back.

  • @voenigs612
    @voenigs612 ปีที่แล้ว +1

    Lots of words and scribbles on paper, but no repairs! 😂👎

    • @mikepanchaud1
      @mikepanchaud1 ปีที่แล้ว +2

      I'd say it has been thoughroly repaired, just waiting for parts. Did you not understand the squiggles?

    • @voenigs612
      @voenigs612 ปีที่แล้ว

      @@mikepanchaud1 I would say you are a victim of manipulation because nothing was actually fixed! Only what I wrote in my first comment happened. Wish you a nice day!

    • @jackofalltrades3727
      @jackofalltrades3727 ปีที่แล้ว

      yes it would have been better for him to have ordered the parts then done the video with the fix more enjoyable @@voenigs612

    • @garygranato9164
      @garygranato9164 ปีที่แล้ว

      @@voenigs612 hey big man why dont you start your own youtube channel and show the rest of us how its done :) :) you could call your channel *voenigs das uber engineer* and you could show the rest of us how to 'magic' parts to your lab with 10 seconds delivery time. yaaaaaay voenigs das uber engineer yaaaaaay :) :)

    • @LearnElectronicsRepair
      @LearnElectronicsRepair  ปีที่แล้ว +3

      This is why we sometimes have Part 2 videos on this channel @@voenigs612 it's a teaching platform not a repair shop 😉 On occasion something crops up in comments which requires an immediate revisit, and I'm not always right. Sometimes the parts turn up and it still doesn't work. On one occasion (apple PSU) the parts turned up, irt ran for two seconds then it blew up spectacularly, on camera! Rest assured if the chip don't fix it we will dive deeper on the channel but I do think in this case there is a very high likelyhood it is a faulty charger chip.