Hi Bob, Greetings from Borneo, your videos inspired me to learn more about electronics. I'm a beginner, was laid off by my employer post-covid years. Now I have more time to learn & practice repairing the electronic board sold by my ex employer to the customers. Fortunately some of the customers still contacted me for help to troubleshoot their machine. At least I can charge them if I manage to fix their machine's power supply to make ends meet. Thanks a lot for your free educational videos 🙏👍👍👍
+Glenn Gacayan I was a tech in the 80s and 90s. These days you simply replace the board/module in many cases. Never tried to solder anything on the boards they make these days, I am not a watchmaker.
Great video and explanations; thank you so much! I'm in the learning stage and your video helped me a lot. I'm new, but I'm learning.... Thank you again Bob.
Excellent video Review!!! I was desperately looking for this info, about how to test check measure Capacitors. At most of my jobs, I just did voltage, continuity and resistance tests checks. But sometimes used to come across capacitor troubleshooting which I had forgotten. Many other "you tubes capacitor videos" talk so much never explain plainly, go to the point, never really explain show so clearly the good capacitor points You made. E.g. specially the one, about BEFORE working testing them YOU HAVE TO DISCHARGE them. You made an awesome video. This video was good similar to the way it was explained taught to us many years ago in College. I was trying to remember had forgotten a lot about capacitors. Awesome review, points explanations you made. Thanks!
Oh, another GOOD Point You made and many others "capacitor videos" fail to explain make a point of, or even mention it, that before measuring test them; you have to Removed the capacitor from the circuit. Makes a lot of sense (get wrong different multimeter readings). Thanks Mr. Bob!!! Thumbs-up to you Sr.!
Hi! In my life, I had to design, to teach, and I was a process engineer in one of world's top SMS capacitors Industries in USA's land. There is a lot to teach. I just mention the basics about capacitors. RU-vid has top guys with great knowledge and teaching videos. But sadly there are also pay by click hunters, laking of knowledge who became famous trying to make videos from the minimum knowledge. It is hard for the knowledge searches to find videos between entertainers and teachers, without to watch one by one until they find what they looked for. Maybe someday RU-vid will create a database, able to classify videos by resume, info, and more specific categories as entertainment or educational in the spoken subject. Thanks Robert by writing. :-)
watching your video from Kenya, Eastern Africa..best well explained and clearer video and educative one. Thanks for that i really needed it BOB. THANK YOU. looking forward to watch a video on --how to test a complete circuit of a Whoofer.
Kenya! Wow! After a cold winter I wish to go there. I had to heat my little electronics lab for hour and a half before to start to work. I will make more videos soon. I was waiting for the temperature to increase. If you see my clothing, in some of my videos, I am wearing 5 t-shirts to record a video. lol Thank you Daiv! :-)
In your clip, around 7:00, you're stating that the band on the capacitor correspond to the outer foil connection. In fact, this should be considered as an ideal situation. I found capacitors that were not marked properly in that regard, having the band on the lead which was connected to the inner side. This discovery is based on a youtube video where the technician was connecting a capacitor on a CRO and based on the noise amplitude introduced while holding the capacitor between fingers. If the amplitude is at its lowest when the band side is connected to the scope's negative lead, then the band on the capacitor is pointing to the outside foil lead, otherwise the band is pointing to the inner one. I've been successful to perform that test only with a CRO. While doing it using a DSO, the results weren't as convincing.
+SimpleEnough2k9 Hi! There is not discovering in RU-vid for anybody. Video: 15:22 The knowledge comes from several decades ago before my father borne! Since the beginning of any electric component, there are a lot of test, investigation, datasheets, and updates to product introduction to main universities and manufactures handbook. All brand cares very well about an electrolytic capacitor's mark. But most brands don't care anymore about the non polar foiled capacitors. And the mark can be on any side or missing that all now day's. In minute 7:15 I sad: " ...many years ago, Fabricants USED to mark where is the outside paper for designers to know"... When we say they used to, it means in English: that it is not use anymore. Evidence of it, is most capacitors alike you will see now days, are missing the mark. I talked about because this knowledge will not escape from the list of cares of any designing engineer. But some "fast food" technical schools let the students to graduate missing that knowledge. Or in the worse situation, people are trying to learn only from RU-vid, and forget to go to school, or to search in books as the main source of formal education. The one that could be confuse about in my video is I didn't talk about Tantalum capacitor. I spoke, but jumped it, leaving it out the subject for next video.
Best regards to my viewer friends from Philippines! (I also have a friend from Philippines at Jacksonville FL, who I consider almost a brother, and I miss other friend who was a great politician from Philippines who already passed away and rest. My blessings to all of you. :-)
Bob kalpon my name is Saleem , I really thank you very much for your effort in making this video I really appreciate everything you have taught me today you are a very nice guy especially at the end when you said dont rely on youtube but look at the books ....so I wanna go to school for that but dont know what to ask for to learn about capacitors and mother board repair like ellectronics repair so please help me go study for it what should i look for? Thank you.
+ckreitlein Thank you! The main idea was to show to test SMD caps and teach some tricks like the right polarization for non polar caps for new designers. Another video is on the way.
+Joseph Gosselin (Popple) Hi! I spoke about how to treat electronics after water in my video: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-ePXSxXqLTA0.html (Use high degree alcohol, a soft brush, and pressure air to rinse it. Other ways, in a few weeks it could become as the laptop in my video: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE--Gh_LXvhap4.html
Hi there , it was great tutorial video . please make a tutorial video about how to read schematic laptop motherboard for beginners, what's means the symbol and how to find voltage for which component and diagnose for repair laptop . thnx
So I did, and learned nothing except how to lift one end of a capacitor (which I already knew). The sound is so bad anyway I didn't know what point the chap was making.
I've got a 250v 150uF Capacitor 105 Celsius which I pulled out of tv main board, checking all the components. It's reading 136 uf on my meter. What do think, number on cap too low to re-use? Or still in range?
hola, tendrás este video en español, busque en tu canal y no lo encontré, me gustan mucho tus videos son geniales y ayudan mucho a personas como yo que les gusta la electrónica como hobby.
Hola bob, excelente video. sabes mi inglés no es muy bueno, así que no entendí todo el video, yo estudio electrónica y tus videos me ayudan mucho a entender muchas cosas que no entiendo en la escuela, y me gustaría pedirte el favor de que si podrias ponerle audio en español a este video, de antemano muchas gracias
Thanks Bob, I'm trying to learn how to fix electronics but as you stated... I'm trying to learn what I think I need to know from RU-vid. What books would you recommend and do you have a supplier for capacitors used in modern LED TV's and motherboards? Since i was a kid I would take my electronics apart and I've seen more than what you showed but not sure what function each type of capacitor is used for?
Hi, thank you so much for your video! Please I need your help! Hi, I'll appreciate if you give me this advice, by chance do you know if the old capacitor 250V PME 271M 0.1 μf X2 40/85/56 it needs to be discharged in the circuit board before remove it or the new one that I got PME 271 M 0.1 μf X2 40/110/56/B how? if so how I can discharge it? With resistance or simple metal? Thank you for your help.
if i have a small smd capacitor like in the end of you video. can you measure continuity between the legs on it to if its short or do i have to remove it first ? why need to remove it, maybe removing only needed when want to read capacitance
If you hold the discharge resistor wire with the metal pliers (you were not holding the insulated part) and if it is 200v and charged, you could give yourself a hell of a zap...
Yes, after 30V we must use insulation. Also the discharge time should be the capacitance times the resistor times 5. Any capacitor after 35V indication must be handled carefully.
+Brett Stafford Thank you! You are welcome. I am working in a video about troubleshooting with SMD devices, and a step by step procedure for electronics fixing. (Updating my old schooling from the 80's to now day's technology).
Hi! Try to get the datasheet for it. In case of there was not data, then you will have to measure it or set up a circuit with a chip 555 to calculate the capacitance value.
in some other dialect besides English maybe, don't folks review there work before posting them? I suppose no one hears their own accent but someone should be giving editorial review input prior to posting.
Thanks Ahmed. Teaching is always a hard task to do. Teaching electronics involves more than pedagogic knowledge or an engineering profession. It is more through the years of experience, where we learn more about student's needs. Education is a stair process. Students learn more and faster as we add more steps and deepest bases. It is the right way to bring a student from zero to the highest level of knowledge. I learned to listen to people and to teach in function of their needs. I am not the best teacher or engineer because I have to enforce to make it for four European languages, for different knowledge levels or professions. In this Channel, I teach only very basic electronics in two languages. Try to be a good student to learn always more. And remember, the only way to measure success is by results. More than half Million people watched my videos and gave already a good feedback to stay on in this RU-vid Channel. This Channel is for people like you an me, from all the world, who search knowledge to be better and to be success. Thanks for writing, and sharing your opinion. Stay close! I there is a group of colleagues, students and friends who are always in touch, and I never forget about them in this Channel.
Hola Bob. Muchas gracias por compartir tus conocimientos. Quiero preguntarte si ese medidor de capacitancia sirve también para toda clase de telefonos moviles como iphone y samsung.
ON MY POWER SUPPLY UNDER IT IT HAS NON CONDUCTIVE PAPER THAT HAS PLASTIC RIVET HOLDING IT UNDER THE CIRCUIT BOARD IS THERE ANY SPECIAL WAY TO REMOVE THE PLASTIC RIVETS OR HAVE SEEN THEM THANK YOU
+wolfenstein1040 Good question! We use 5 Watts, 10 or 25 Watts resistors. Any value in Ohms between 100 to 4.7K can be OK. (In reality any good resistor from the ones you have on hand). There is a capacitor discharge formula = [5 x (R x C)]. R is the resistor in Ohms, C is the capacitor in Faraday, and multiplied 5 times. BUT, that "5" is a constant number used for a good connection discharge. So, for safety, YOU MUST last about 3 times the value of the formula, once you made a good contact between them. ;-) (Try to find high Ohms resistors for the main high Voltage capacitors discharge. The lower of the resistor, the higher of the Watts for it)!
Hi! You have to do two tests. - One is continuity to ground: negative lead on ground, and touch both sides of the capacitor with the positive lead of the tester. In some capacitors, there will be continuity to ground in one side, but no the other side. - The other is continuity, and better with Ohms meter, in both sides of the capacitor. There should not be short circuit or low resistances. For anything suspicious, remove one side of the smd capacitor for capacitance meter test. A lot of the capacitors are 0.1 uF in parallel with everything just to bypass noise. Those ones, get shorted in laptops, tablets, and smartphones, making a whole area in short. You can remove it, and everything will work. It happens a lot, because the Voltage rate is low on them, and become sensitive with the time and easy to short circuit. :-)
For the first test: continuity with a "beep" sound to work faster. For the 2nd test: Ohms meter. If one of them looked suspicious, remove the solder in one side or the component that all and measure it with the "CAP" or "-I I-" symbol in the DMM dial if it is available in your DMM, or with a capacitor meter. DO NOT FORGET to always discharge the capacitor with a short circuit before to perform a measurement. ;-)
what do you set your multimeter at to test the photo cell in my motion sensor light. the light works but the light will come on even in the daylight, so i want to test the board and i think its a cds, marked on the board?
Hi! For a simple photo cell test use Ohms meter. For function test, use voltage meter. The best way to get a good result is to set up a "window comparator circuit". It can be done with 2 Operational Amplifiers. I recommend to use the ones that works OK with +V and Gnd, and voltage between 3 and 5 Volts if it is the case. Set the voltage level upper of 160mVolts. (The better is something close to half Vcc). There are low noise comparators too. If you work with photocells or phototransistors, you must make the window comparator in order to control the light's hysteresis or to reduce the noise's effects.
