Excellent video Richard, please keep doing the hand drawn sketches, it really helps understand what is going on in the circuit you are describing as you diagnose it. This is the best repair channel for explaining the principle of how the circuit works.
I really appreciate that you worked out the fix without ever plugging in the board or looking up datasheets - it means a deeper understanding of the circuit which I appreciate, and has a detective element to it too :)
That little toroidal coil has only eight wraps. It would have been nice to watch you rewind it to "wrap up" the repair. Once again I enjoyed how you reverse engineer and document the circuit to get to the root of the problem. Cheers!
I found that you explained it very clearly and this power supply is not overly complicated. But as we went through the diagnosing I 1st suspected the FULL BRIDGE RECTIFIER (Thank you Electroboom I have to say this every time now.) 2nd the X2 Capacitor and 3rd The mains cable itself, I never thought the inductor would fail like that. But I'm sure I would have got there in the end, it's just a case of removing parts until the short is gone. Would love to see a video on class X and Y capacitors.
I had situation, where inductor, was properly soldered, but thin wire of inductor, was desoldered from contact leg, so depending of vibrations or angle of pcb, it had contact and worked, another time not. Only when I removed isolation from inductor and checked with microscope I saw loose wire. Never say "its not this" without proper check.
Having fixed a good number of supplies (switchers) its the 1st time to see a choak like that short out. Factory defect or harsh handling is only way I would explain it. Great explanation of the transformer in a switcher for the high/low coils!
Great video, I have had those filter chokes go short, especially on chepo Chinese equipment. The 4 pins are probably for current monitoring or battery balancing as this may be for a lithium iron or Lypo battery where each cell is balanced charged.
Hi Rich, Interesting content, but as you say, if you were doing it to fix the thing, you'd check the fuse and check for shorts first. If I was Andy, I'd send you more hardware (case and battery) so you could test and be confident it works. The battery might have an issue as well. Thanks for the commentary and diagrams. E.J.
I have some battery tools, like screwdrivers, a little mini rotary saw....I checked and all them chargers blink the LED when charging, and lit It solid when fully charged. (various brands, various models). If the battery is in bad condition (i.e. soooo low voltage Nickel ones), They do not turn the LED on , indicating "bad one". Nice finding, that shorted inductor. Giving the "caliber" of those wires, not having a fuse could have resulted in an interesting "boom!"
I’m so sorry. After almost a year I neglected to subscribe. Shall do on every one I rewatch. Your material is great and I actually enjoying mucking around on the boards. A bit older, a little late but will be happy to die with a breadboard in my hand.
the capacitor for sure is a X rated self healing safety cap it is very unlikely to go short... on the other hand the coil its also not normally short lol only by defect
Nice reverse engineering of the circuit, Richard! I'm sure eventual short wave listeners in the vicinity would appreciate the lower noise level in their receivers if this first filter choke were in the circuit still :)
I had situation, where inductor, was properly soldered, but thin wire of inductor, was desoldered from contact leg, so depending of vibrations or angle of pcb, it had contact and worked, another time not. Only when I removed isolation from inductor and checked with microscope I saw loose wire. Never say "its not this" without proper check.
On tool battery chargers the outer two pins are B+ and B-. The inner 2 pins are sense pins for temperature of the battery and whatever else might be monitored.
When looking for shorts around coils, why not use what we learned with CPU/GPU VRMs? That is, not measure DC Ohms, but AC (milli-)Ohms, like with an LCR meter? Also noteworthy is the yellow cap should be an X2 cap, and they are designed to go open instead of the short you see on other cap types.
How do you charge the customer, your time must be worth more than the charger? I can understand if it is obsolete equipment that needs to be kept going but other wise I can not see why a new one is not bought.
For this sort of job I would charge him €20. The reasons for fixing it would be that it is cheaper than replacing the drill, he can get back to work using it rather than driving up to the capital to find a replacement charger (it's about 80km round trip) or waiting a month for one to arrive in the post. The way of life on a small remote island is generally to keep things going rather than replace them. The Canary Islands are an interesting place, we have all the infrastructure of a developed western country - 92% fibre optic cover for example - but the economy of an African country, typical pay is about €1000 a month for general workers. I know the lady who is the manager in one of the local Vodafone shops, salary €1100 per month. On the other hand it is cheaper to live here too, For example the office/shop I rent, 30m2 in a local shopping centre is €295 per month and my electricity bill (3 bedroom house) is around €60 per two months, we don't have mains gas on the island, so €20 for this job would pay my home energy bill for nearly three weeks or deisel for my van for 10 days. I will also get some payment from the video sponsor so went the long way round what would normally be a quick repair. That seems fair to me. How much would it cost to replace the drill? I don't k now as I don't know the model but it must be a lot more than that.
@@LearnElectronicsRepair Thanks for the very extensive reply.Your electric bills are far far cheaper than the UK. I am being charged £148 a month for 350 units of electricity.
@@tonysheerness2427 Really it all seems to come down to where you are in the world whether something is worth repairing or not. There is also the environmental issue too, which I feel is important.
@@LearnElectronicsRepair Yes they complain about plastics however they keep bringing out more and more plastic products. To me it is if the people always get the blame for large companies making profits who do not care about the environment.
@@LearnElectronicsRepair Since the arc'ing on that inductor was right on the end of the wire, Rich, maybe you could repair it with a little heat-shrink and re-use it? Thanks.
The two centre battery contacts don't appear to be connected to anything Richard? You seem to be getting 0V across the two outer battery contacts. A further fault I think.
I read about 3V across them. As: I don't have the drill or even the enclosure which would have a voltage rating marked on it I found an obvious fault and usually there is one fault on an item The nature of the fault I found is unlikely to be caused by, or to be the cause of, another fault in the circuit I think the best thing is to give it to Andy and tell him if it doesn't work bring it back with the drill
Dicky, it would’ve been better to have the battery at the end of this video, to actually make it true, in the fix, why you only got the board is strange.. or did your friend blow it up in the first place, people will be asking the question’s , as I’ve just pointed out, good fix, but only half hearted, if a friend or client want you to fix something, it’s got to be complete, to test at the end, prior to ringing them and asking for the missing piece.. aka the part it’s supposed to run.. (honestly it’s the only way to see if you’ve fixed it properly.. ).
Andy deals with the customers and pays me for the repair work - that suits me if he can make a profit from it and it is much less hassle for me - win win as I see it. Plus I get a lot of interesting material to feed my videos. All is good,
Excellent video Richard, please keep doing the hand drawn sketches, it really helps understand what is going on in the circuit you are describing as you diagnose it. This is the best repair channel for explaining the principle of how the circuit works.
I really appreciate that you worked out the fix without ever plugging in the board or looking up datasheets - it means a deeper understanding of the circuit which I appreciate, and has a detective element to it too :)
Excellent teacher, he can clearly explain WHY he does things and what his thinking process is.
Great job Richard, your reverse engineering skills are second to none. Love the detailed and well explained functions of the various circuits 👍
That little toroidal coil has only eight wraps. It would have been nice to watch you rewind it to "wrap up" the repair. Once again I enjoyed how you reverse engineer and document the circuit to get to the root of the problem. Cheers!
My thoughts entirely, winding inductors easy
@@davet3804 I did give it a thought, but it was all gummed up with very hard epoxy or something similar so I decided not to.
I like how you take the long way around, because I always learn something new that way.
Great video, you've certainly teached me a lot!
Also, hand-drawn schematics + their explanations help a lot!
I found that you explained it very clearly and this power supply is not overly complicated. But as we went through the diagnosing I 1st suspected the FULL BRIDGE RECTIFIER (Thank you Electroboom I have to say this every time now.) 2nd the X2 Capacitor and 3rd The mains cable itself, I never thought the inductor would fail like that. But I'm sure I would have got there in the end, it's just a case of removing parts until the short is gone. Would love to see a video on class X and Y capacitors.
I had situation, where inductor, was properly soldered, but thin wire of inductor, was desoldered from contact leg, so depending of vibrations or angle of pcb, it had contact and worked, another time not. Only when I removed isolation from inductor and checked with microscope I saw loose wire. Never say "its not this" without proper check.
I really enjoy your SMPS videos - I learn something with each one. Thank you for sharing your knowledge.
Thank you Richard! For another excellent repair instruction video. I enjoy your informative content. Keep the excellent videos coming!
Great watch. Just love the way you explain and draw it out. 😁
Muy buen video, muchas gracias ingeniero, saludos desde PERÚ 🇵🇪 👍
Having fixed a good number of supplies (switchers) its the 1st time to see a choak like that short out. Factory defect or harsh handling is only way I would explain it.
Great explanation of the transformer in a switcher for the high/low coils!
thanks, you are a true teacher
As always love your repairs Richard! Thank you for sharing!
My favourite channel on TH-cam and it’s inspired me to try to take on some repairs of my own. Could you do a few on LED/plasma tv repairs?
Great video, I have had those filter chokes go short, especially on chepo Chinese equipment. The 4 pins are probably for current monitoring or battery balancing as this may be for a lithium iron or Lypo battery where each cell is balanced charged.
Hi Rich, Interesting content, but as you say, if you were doing it to fix the thing, you'd check the fuse and check for shorts first. If I was Andy, I'd send you more hardware (case and battery) so you could test and be confident it works. The battery might have an issue as well.
Thanks for the commentary and diagrams. E.J.
Thanks for explaining your thoughts as you go, really informative. Great channel.
Another cracking video Richard. Keep 'em coming!
Very well explained. Keep up the great work 😀👍
Great demonstration video.....thanks, Rich.
I have some battery tools, like screwdrivers, a little mini rotary saw....I checked and all them chargers blink the LED when charging, and lit It solid when fully charged. (various brands, various models). If the battery is in bad condition (i.e. soooo low voltage Nickel ones), They do not turn the LED on , indicating "bad one". Nice finding, that shorted inductor. Giving the "caliber" of those wires, not having a fuse could have resulted in an interesting "boom!"
I’m so sorry. After almost a year I neglected to subscribe. Shall do on every one I rewatch. Your material is great and I actually enjoying mucking around on the boards. A bit older, a little late but will be happy to die with a breadboard in my hand.
the capacitor for sure is a X rated self healing safety cap it is very unlikely to go short... on the other hand the coil its also not normally short lol only by defect
Great video, thank you and I did learn something!
Nice reverse engineering of the circuit, Richard! I'm sure eventual short wave listeners in the vicinity would appreciate the lower noise level in their receivers if this first filter choke were in the circuit still :)
Very well explained! I learned a lot. Thank you!
I had situation, where inductor, was properly soldered, but thin wire of inductor, was desoldered from contact leg, so depending of vibrations or angle of pcb, it had contact and worked, another time not. Only when I removed isolation from inductor and checked with microscope I saw loose wire. Never say "its not this" without proper check.
On tool battery chargers the outer two pins are B+ and B-. The inner 2 pins are sense pins for temperature of the battery and whatever else might be monitored.
Cheers.
Heya, very rear those coils burn true and make a short good you found it
When looking for shorts around coils, why not use what we learned with CPU/GPU VRMs? That is, not measure DC Ohms, but AC (milli-)Ohms, like with an LCR meter?
Also noteworthy is the yellow cap should be an X2 cap, and they are designed to go open instead of the short you see on other cap types.
How do you charge the customer, your time must be worth more than the charger? I can understand if it is obsolete equipment that needs to be kept going but other wise I can not see why a new one is not bought.
Very good point but this is educational stuff more than just about money :)
For this sort of job I would charge him €20. The reasons for fixing it would be that it is cheaper than replacing the drill, he can get back to work using it rather than driving up to the capital to find a replacement charger (it's about 80km round trip) or waiting a month for one to arrive in the post. The way of life on a small remote island is generally to keep things going rather than replace them. The Canary Islands are an interesting place, we have all the infrastructure of a developed western country - 92% fibre optic cover for example - but the economy of an African country, typical pay is about €1000 a month for general workers. I know the lady who is the manager in one of the local Vodafone shops, salary €1100 per month. On the other hand it is cheaper to live here too, For example the office/shop I rent, 30m2 in a local shopping centre is €295 per month and my electricity bill (3 bedroom house) is around €60 per two months, we don't have mains gas on the island, so €20 for this job would pay my home energy bill for nearly three weeks or deisel for my van for 10 days. I will also get some payment from the video sponsor so went the long way round what would normally be a quick repair. That seems fair to me. How much would it cost to replace the drill? I don't k now as I don't know the model but it must be a lot more than that.
@@LearnElectronicsRepair Thanks for the very extensive reply.Your electric bills are far far cheaper than the UK. I am being charged £148 a month for 350 units of electricity.
@@tonysheerness2427 Really it all seems to come down to where you are in the world whether something is worth repairing or not. There is also the environmental issue too, which I feel is important.
@@LearnElectronicsRepair Yes they complain about plastics however they keep bringing out more and more plastic products. To me it is if the people always get the blame for large companies making profits who do not care about the environment.
Great explanation!
do you have any vidoes of led lcd tv i need them
I am not sure why this charger needs 2 common mode chokes maybe because of there different size could be for filltering different frequences
Can you please advise the rated insulation voltage rating of these solder stick devices?
I will find out
@@LearnElectronicsRepair Thanks that would be terrific 👍
Thank you. Couldn't you remind that?
lots of useful info in this video :)
would a mico ohm meter speed things up
Bravo
Hi, where are your shop? Id like to visit you
great diagnosis, but I'm confused lol. The inductor coil was replaced with a fuse yes? So thats the fix? did I miss something?
No - I slightly messed up the video edit, i replaced the filter inductor with two wire links, then replaced the fuse
@@LearnElectronicsRepair Thanks
@@LearnElectronicsRepair Since the arc'ing on that inductor was right on the end of the wire, Rich, maybe you could repair it with a little heat-shrink and re-use it? Thanks.
The two centre battery contacts don't appear to be connected to anything Richard? You seem to be getting 0V across the two outer battery contacts. A further fault I think.
In some models they maybe 'sense' connections for current or core temperatures.
@@andymouse Absolutely. But not in this case!
@@gman7692👍
I read about 3V across them. As:
I don't have the drill or even the enclosure which would have a voltage rating marked on it
I found an obvious fault and usually there is one fault on an item
The nature of the fault I found is unlikely to be caused by, or to be the cause of, another fault in the circuit
I think the best thing is to give it to Andy and tell him if it doesn't work bring it back with the drill
Dicky, it would’ve been better to have the battery at the end of this video, to actually make it true, in the fix, why you only got the board is strange.. or did your friend blow it up in the first place, people will be asking the question’s , as I’ve just pointed out, good fix, but only half hearted, if a friend or client want you to fix something, it’s got to be complete, to test at the end, prior to ringing them and asking for the missing piece.. aka the part it’s supposed to run.. (honestly it’s the only way to see if you’ve fixed it properly.. ).
I am an old cynic. Is Andy passing these repairs off as his own? If he is then is there a mark up?
Andy deals with the customers and pays me for the repair work - that suits me if he can make a profit from it and it is much less hassle for me - win win as I see it. Plus I get a lot of interesting material to feed my videos. All is good,
@@LearnElectronicsRepair sounds good.
neanderthal can do anthyting when he puts his mind to it
it might not have been the battery charger it could be faulty batteries not accepting a charge
Tutorial Controlador MPPT - Parte 1 th-cam.com/video/jxzj8Pp_xJw/w-d-xo.html