PCBWay 3D Printing and Fabrication: www.pcbway.com/rapid-prototyping/ Support the Channel with Patreon: www.patreon.com/sdgelectronics At 15:02, this is a voltage doubler network for 115V AC input.
@ckm-mkc unscrew the back panel, then apply some heat to loosen up the adhesive (you can just pull it off, but it's easier with heat). There is a bunch of screws behind the panel. Then pull the back out and the side will fall off
What a great video, Steve. Your diagnostic skills are brilliant. Nice little amplifier. Can we please see more of this type of video, I really enjoyed every minute of it. Thanks for sharing.
@@sdgelectronics I hope you can as this video was a very interesting and a good watch, enjoyed the detail that you took the time to go into and the explanations.
One of the best repair video I have watched in a long time. Excellent thought process and explanations. I have also been fighting this awful glue with the famously flawed Jarre Tower speakers retailing for a stupid amount of money. The PSU and power stages were covered with this corrosive junk and I became the world expert in repairing these 🤣 At some point the manufacturer just stopped their activity and sent me their customers for repairs. I traced the issue to a Chinese factory that built these boards and was using this glue. I still don't know if they use this glue on purpose to shorten the life of the products but it could be the case. Thanks for the great video!
Hi Steve, just wanted to say your electronics repair guide is the best I’ve seen. You explained everything so clearly and thoroughly, which is rare to find. It’s clear you have a great talent for this, and I really hope you make more videos like this. Thanks for sharing your knowledge!
The dreaded brown glue. You would think after all these years that they would have ceased to used it as it's ability to eat the PCB has been known about for many years. Very nice video.
That was a really enjoyable video Steve and first rate. You have a really good logical approach to fault finding with good interpretation of the schematic. Definitely a really nice a repair video to watch and a few more in the future would be very welcome. You may not wish to answer this but could you give an ideal of service hours for this repair. Many thanks Ian
Another big thumbs-up here. A great video. Some really thorough trouble-shooting and repairs. Good camera work too. Kept me up way past my bedtime. Thanks!
Love this sort of repair videos! A bit advanced for me in terms of following the schematic, but I did pick up some of the practical aspects such testing whether some components are working, cheching the vias etc. The high level thinking and thought process were also helfpful. Would love to see more and perhaps at a slower pace on reading the diagrams. Looking forward to the next video.
Great video. These Hypex modules run quite hot, possibly accelerating the glue degradation. The first version was even worse for heat due to the under-specced output inductors. I see this newer version has open toriodal inductors, whereas V0 had upright bobbin types.
Very informative repair Steve, nice to see one! I'm always impressed by how you "Young Bucks" are able to understand newer devices and analyze both the Analog and the Digital. Very well done Sir! I learned a lot. - JRH
Nice repair Steve. Those damn glue, i remember the same exact glue from entry level amp made in japan in the 80's. Still the manufactures keep using those damn glue.
I've replaced so many current sense resistors. You'd kind have thought something would sense too much current and protect them, but there you go! They do usually fail when a SMPS MOSFET fails but I guess downstream can do the same thing.
Great informative video, brilliant detective work tracking down the faults. I often wonder why we complicate electronic devices by building in standby circuits. Are we really too lazy to use a physical, longer lasting, less complicated, cheaper and safer on off switch.
Excellent video, thanks. Please do more repair videos! I particularly like classic hifi and valve amps, so perhaps you could buy some spares/repairs kit on the website and do them up for resale?
Awesome content, great work ! Personally though I was a little disappointed with the build quality but that's just me not liking capacitors on the pee and regulators lying down I expected a bit better from NAD, loved the repair.
Yeah, the schematics show really good design decisions, but the assembly doesn't match it. I also spotted a couple of layout errors, one electrolytic capacitor didn't even get routed out? 😮 Did they not run the DRC? 😂
I know a lot of electronics but I am finding the learning curve to be steep on some repairs. I love the verbal thought process & depth of the repair and would love more at this detail. I also like to follow how you bench test the sections with scopes, power supply etc. Also you didn’t mention where the replacement MOSFETs came from, assuming not China but thru a reputable parts supplier.
I wonder if this problem is unique to the Hypex module in the NAD units. These Hypex boards are available to the diy market as well, hopefully folks who built these a few years ago don't have conductive glue!
Very thorough diag & repair - nice one. A cynical person might suspect that these manufacturers know full well what happens to these glues over time and are perfectly happy about it.....a slightly less cynical person might suspect that the Chinese manufacturers they all use are less scrupulous than one might like and are using cheap alternatives to the specified adhesives. An entirely non-cynical view might be that the manufacturers have been duped, a bit like the old fake capacitor electrolyte scandal from a few years back. Whichever is true, it seems a good first step with anything like this is to remove all traces of adhesive, inspect very carefully for damaged traces & vias and go from there.
25:03 Surely if they are using current sensing for the feedback and they know the values of the current sensing resistors, then simply by using ohms law you know the voltage.
Thanks. Very useful and educational. I would definitely prefer the TEAC amps over these. The ICEpower amplifier modules used on most of TEAC amps are of much higher quality and their devices are generally of much better design and implementation.
Hypex modules, especially the newer Ncore(x) and newest Nilai modules outperform any class D (except some Purifi modules) and 90% of class A/B amps out there on basically all metrics. And, they're much more efficient of course.
Hello Steve, I can't believe this but your video comes 3 days before my own beloved D3020 has just gone pop. It's especially brilliant as there's very little out there about this brill little amp. Mine powers up fine after its startup routine on the front panel but on startup it sends a big pop out of the left channel and there's no sound from the left channel at all. The front panel is very DIM compared to when it was new and the sound level is severely reduced too. Any ideas 🙏
Are all of the LEDs on the front panel the same brightness? It could be the phosphor on the LEDs have degraded, or a low supply voltage. For the pop/no sound, you'd need to probe the audio into the Class D amplifier to see if audio is making it out of the preamp/input switch/volume control. The pop suggests you're getting DC somewhere in the audio chain.
@@sdgelectronics Hi Steve, thanks for getting back to me. No, the LEDs are not all the same brightness. Thé lower numbers are very dim but thé source LEDs are brighter towards the bottom. I can live without the panel per say but something on the amp side has definitely gone! Such a shame. Wish you all the best with yours!
I have a newer model of this DAC amp, it's a nice package, easy to setup and use with the 1 large volume knob, but the capacitive touch mode select button NAD replaced with a 1/2 size indexing rotary knob. Surprisingly powerful, and accepts all music formats and resolutions seamlessly. However. The digital volume function has random drift up or down creating frustrating slow volume decrease or dangerous volume increase. Volume drift has occurred while powered on but not in use, resulting in catastrophic speaker damaging sound explosion on unaware music start. NAD has been a favourite brand for decades owning value for money, innovative technology, and surviving in the fickle high cost high end audio market. They don't often make mistakes but when they do they're huge and weird - they were early proponents of direct digital including volume control, you'd think they'd just get it right. Apropos of this excellent video id'd problem of the pcb component glue. Design of packaged electronics is my profession, and I've had numerous debates with electronic engineers and pcb layout people on large component mounting. As Hypex OEM's these amp modules, they don't know or control where or how they're used, so it is a smart design to provide additional large component mounting. Glues are also used for vibration isolation, tamper proofing, and sometimes obscure and weak argument for creepage and clearance issues. Hypex would have specified a glue, but they might have left the glue selection up to whatever the contract manufacturer was already using, this is typical procedure. I'm a proponent of mechanical mounted securing and vibration isolation, with tamper proof connections if required.
Replace all the capacitors, but that was final.Output transistors, are your problem.Then use garbage in the final outputs to save a book upgrade and get better quality
NAD we're always a bit cheapo in terms of construction but this just looks like standard Chinese contract manufacturing standards to me. Skimping on components, glue used everywhere in lieu of better quality connectors, general lack of attention to detail. No different to any other piece of cheap tat, except this wasn't cheap.
NAD, gear was usually a bit like spaghetti junction once you removed the cover (wires everywhere, not as bad as most Aiwa cassette decks !), always sounded good, but not well assembled.
Hey Steve, I tried to contact you on your website but no luck . I always enjoy your videos, especially reviews and products disassembly. I have one favor to ask you though. Could you please 🙏 review and disassemble JBC CLMU ? It would be very appreciated . JBC CLMU is one of a kind. The industry is lacking an automatic tip cleaner with such finish.
I think I would bypass the via's regardless the same way you did. Also if using silicone to provide some support for the caps remember to use silicone that's not got acetic acid e.g the natural slow curing version. I also have the old analogue NAD 3150 amp which has great sound through a pair of B&W speakers. I'd love to say a pair of Nautilus speakers, but just a pair of 100's i think they are. 😞
The mod you did there was a very bad ideea! By doing that you disabled the current sense of the OCP corcuit! :) What you should do is change that current sense power rezistors! :)
I have seen that black glue mess up powered speakers before, and that was years ago. I suspect that it is a planned obsolescence 'feature' at this point. I refuse to believe the designers don't know to not use that stuff by now.
Hi Steve. Would you do a repair on a small battery charging board/lithium battery pack? Or do not take any work on through here, or would you give me some help? Just you have no contact details on here. If not, no worries. Cheers Rick
9 times out of 10 with that clash amplifire. When it does that when you hit the power and it goes through a cycle and it shuts back off. You have a direct short on the final output of the amplifier 9 times out of 10. It's never the power supwhy. It's always the final output stage of the amplifier. You can save yourself a lot of problems.You go right to that source.You pull the final output?Believe output, stage the power amp.Out and you Check the finals and you would Save yourself a lot of time That brand N a d is notorious Especially that type of amplifier for having The finals going bad It's a good amplifier , but they use lousy finals If I were you , I would not put the same ones in there I would find comparable ones that wouldn't give you the same Output or better at the same voltage And ambridge don't Replace what the same make Do Yourself a Favor and upgrade Spend a few more shekels
Well people would be wise to avoid buying these on the second hand market. Using that glue was plain stupid. Board damage has been known for decades now from glue gone conductive. Not having any sort of output protection also is being cheap.
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At 15:02, this is a voltage doubler network for 115V AC input.
How did you get the D3020 out of the case? Trying to fix one of these but disassembly is, er, difficult.
@ckm-mkc unscrew the back panel, then apply some heat to loosen up the adhesive (you can just pull it off, but it's easier with heat). There is a bunch of screws behind the panel. Then pull the back out and the side will fall off
What a great video, Steve. Your diagnostic skills are brilliant. Nice little amplifier. Can we please see more of this type of video, I really enjoyed every minute of it. Thanks for sharing.
Thanks Brian, I'll see if I can find other items worth repairing
@@sdgelectronics I hope you can as this video was a very interesting and a good watch, enjoyed the detail that you took the time to go into and the explanations.
One of the best repair video I have watched in a long time. Excellent thought process and explanations. I have also been fighting this awful glue with the famously flawed Jarre Tower speakers retailing for a stupid amount of money. The PSU and power stages were covered with this corrosive junk and I became the world expert in repairing these 🤣 At some point the manufacturer just stopped their activity and sent me their customers for repairs. I traced the issue to a Chinese factory that built these boards and was using this glue. I still don't know if they use this glue on purpose to shorten the life of the products but it could be the case. Thanks for the great video!
Hi Steve, just wanted to say your electronics repair guide is the best I’ve seen. You explained everything so clearly and thoroughly, which is rare to find. It’s clear you have a great talent for this, and I really hope you make more videos like this. Thanks for sharing your knowledge!
First competent person clipping the components legs before soldering them in place. I commend you. You are obviously from a production environment.
The dreaded brown glue. You would think after all these years that they would have ceased to used it as it's ability to eat the PCB has been known about for many years. Very nice video.
That was a really enjoyable video Steve and first rate. You have a really good logical approach to fault finding with good interpretation of the schematic. Definitely a really nice a repair video to watch and a few more in the future would be very welcome. You may not wish to answer this but could you give an ideal of service hours for this repair. Many thanks Ian
Overall it was about 4 to 6 hours from start to finish.
Respect! You talking through your diagnostic approach is very helpful, Steve. Thanks for sharing.
What an epic fix!!! I love everything about this video, well explained , plenty of physical detail shown
Excellent video that demonstrates your understanding on the topic till the very end, when you’ve checked for DC 😂 at the terminals.
Nice repair Steve, very well presented. Nice amp for your workshop, very compact.
Seems to work well, though it does get warm given there's virtually no airflow. The connectivity is quite useful though
Really enjoyed step by step troubleshooting guide. Would love to see more of such repairs.
Thank you for taking us along for the repair-journey, Steve. I hope that amplifier brings you years of service and enjoyment!
The average repair guy would have had a tough time with that one! Nice work! Nice to see a repair video. Thanks
Repair type content much appreciated to see here!
Mad repair! That looks painful to work on! Love how you methodically went through the fault finding process, so much was wrong with that thing!
Excellent diagnostic skill, Beautifully explained with the CKT diagram , stage by stage Thanks Steve, for your commitment Hats off
Another big thumbs-up here. A great video. Some really thorough trouble-shooting and repairs. Good camera work too. Kept me up way past my bedtime. Thanks!
Love this sort of repair videos! A bit advanced for me in terms of following the schematic, but I did pick up some of the practical aspects such testing whether some components are working, cheching the vias etc. The high level thinking and thought process were also helfpful. Would love to see more and perhaps at a slower pace on reading the diagrams. Looking forward to the next video.
Nice repair video Steve. Makes a nice change to the channel output. Thanks for putting that one together.
Great video. These Hypex modules run quite hot, possibly accelerating the glue degradation. The first version was even worse for heat due to the under-specced output inductors. I see this newer version has open toriodal inductors, whereas V0 had upright bobbin types.
Ah I saw some pictures with enclosed inductors. I wasn't sure if it was someone's modification
Great repair video! You definitely “earned“ your success on this one - not a replaced blown fuse repair by any stretch.
Really enjoyed this Steve - like others I am enjoying the repair videos! Thanks.
Very informative repair Steve, nice to see one! I'm always impressed by how you "Young Bucks" are able to understand newer devices and analyze both the Analog and the Digital. Very well done Sir! I learned a lot. - JRH
Nice repair Steve. Those damn glue, i remember the same exact glue from entry level amp made in japan in the 80's. Still the manufactures keep using those damn glue.
Excellent work and thank you for the explanations as you progressed, really enjoyed watching.
I've replaced so many current sense resistors. You'd kind have thought something would sense too much current and protect them, but there you go! They do usually fail when a SMPS MOSFET fails but I guess downstream can do the same thing.
Great informative video, brilliant detective work tracking down the faults.
I often wonder why we complicate electronic devices by building in standby circuits. Are we really too lazy to use a physical, longer lasting, less complicated, cheaper and safer on off switch.
Great video Steve, so much knowledge, I wish i had half or a quater your ability
Nice to see repair video from you thank you for the explaining well how to troubleshoot something, really nice video.
Well done! Glue has been an issue for decades, I'm surprised they don't opt for something more neutral.
I've seen some pictures of newer versions (2016+,still V1 pcb) module using silicone type adhesive.
I still have two working NAD 3020 analogue amplifiers in my family, I don't think I'll be opting for the digital version anytime soon!
Excellent video, thanks.
Please do more repair videos! I particularly like classic hifi and valve amps, so perhaps you could buy some spares/repairs kit on the website and do them up for resale?
Thank you for the video. I prefer repairs.
Love the repair videos. Subbed.
Thank you so much, I genuinely loved the repair
Excellent video. Thanks for making and sharing.
Awesome content, great work ! Personally though I was a little disappointed with the build quality but that's just me not liking capacitors on the pee and regulators lying down I expected a bit better from NAD, loved the repair.
Yeah, the schematics show really good design decisions, but the assembly doesn't match it. I also spotted a couple of layout errors, one electrolytic capacitor didn't even get routed out? 😮 Did they not run the DRC? 😂
@@sdgelectronics LOL ! :)
I know a lot of electronics but I am finding the learning curve to be steep on some repairs. I love the verbal thought process & depth of the repair and would love more at this detail. I also like to follow how you bench test the sections with scopes, power supply etc. Also you didn’t mention where the replacement MOSFETs came from, assuming not China but thru a reputable parts supplier.
Yes all parts from RS on the UK. I'll talk through the testing setup in the next one
Good piece every once in a loooong while 👍
Well done, good review. I like the style of the amp, but your right it's going to fail at some point.
I wonder if this problem is unique to the Hypex module in the NAD units. These Hypex boards are available to the diy market as well, hopefully folks who built these a few years ago don't have conductive glue!
I've seen pictures of various adhesives used on these boards, not sure if Hypex spec the glue or the pcb assembler
Really enjoyed this repair video.
Very thorough diag & repair - nice one. A cynical person might suspect that these manufacturers know full well what happens to these glues over time and are perfectly happy about it.....a slightly less cynical person might suspect that the Chinese manufacturers they all use are less scrupulous than one might like and are using cheap alternatives to the specified adhesives. An entirely non-cynical view might be that the manufacturers have been duped, a bit like the old fake capacitor electrolyte scandal from a few years back.
Whichever is true, it seems a good first step with anything like this is to remove all traces of adhesive, inspect very carefully for damaged traces & vias and go from there.
Very good repair video 👍 Thank you
More repair videos would be nice! Cheers
great video my brotha.
25:03 Surely if they are using current sensing for the feedback and they know the values of the current sensing resistors, then simply by using ohms law you know the voltage.
Loved the video. Darn bleeping glue.
Thanks. Very useful and educational. I would definitely prefer the TEAC amps over these. The ICEpower amplifier modules used on most of TEAC amps are of much higher quality and their devices are generally of much better design and implementation.
Hypex modules, especially the newer Ncore(x) and newest Nilai modules outperform any class D (except some Purifi modules) and 90% of class A/B amps out there on basically all metrics. And, they're much more efficient of course.
Great job. A bit of a worry for owners of these NAD's
Brilliant!! Thank you!
Hello Steve, I can't believe this but your video comes 3 days before my own beloved D3020 has just gone pop. It's especially brilliant as there's very little out there about this brill little amp.
Mine powers up fine after its startup routine on the front panel but on startup it sends a big pop out of the left channel and there's no sound from the left channel at all. The front panel is very DIM compared to when it was new and the sound level is severely reduced too.
Any ideas 🙏
Are all of the LEDs on the front panel the same brightness? It could be the phosphor on the LEDs have degraded, or a low supply voltage. For the pop/no sound, you'd need to probe the audio into the Class D amplifier to see if audio is making it out of the preamp/input switch/volume control. The pop suggests you're getting DC somewhere in the audio chain.
@@sdgelectronics Hi Steve, thanks for getting back to me.
No, the LEDs are not all the same brightness. Thé lower numbers are very dim but thé source LEDs are brighter towards the bottom.
I can live without the panel per say but something on the amp side has definitely gone! Such a shame.
Wish you all the best with yours!
Great video!
I have a newer model of this DAC amp, it's a nice package, easy to setup and use with the 1 large volume knob, but the capacitive touch mode select button NAD replaced with a 1/2 size indexing rotary knob. Surprisingly powerful, and accepts all music formats and resolutions seamlessly. However. The digital volume function has random drift up or down creating frustrating slow volume decrease or dangerous volume increase. Volume drift has occurred while powered on but not in use, resulting in catastrophic speaker damaging sound explosion on unaware music start. NAD has been a favourite brand for decades owning value for money, innovative technology, and surviving in the fickle high cost high end audio market. They don't often make mistakes but when they do they're huge and weird - they were early proponents of direct digital including volume control, you'd think they'd just get it right.
Apropos of this excellent video id'd problem of the pcb component glue. Design of packaged electronics is my profession, and I've had numerous debates with electronic engineers and pcb layout people on large component mounting. As Hypex OEM's these amp modules, they don't know or control where or how they're used, so it is a smart design to provide additional large component mounting. Glues are also used for vibration isolation, tamper proofing, and sometimes obscure and weak argument for creepage and clearance issues. Hypex would have specified a glue, but they might have left the glue selection up to whatever the contract manufacturer was already using, this is typical procedure. I'm a proponent of mechanical mounted securing and vibration isolation, with tamper proof connections if required.
The black glue is anti vibration to stop the heavy caps snapping off during transport
The conductive glue issue is decades old, so I assume the glue is deliberately added to give a finite life to the product.
Replace all the capacitors, but that was final.Output transistors, are your problem.Then use garbage in the final outputs to save a book upgrade and get better quality
To compare, I just repaired an older KEF amplifier, and they were not helpful at all in providing service manual or anything really.
It all looks a bit thrown together sadly. I don't think NAD are what they once were.
NAD we're always a bit cheapo in terms of construction but this just looks like standard Chinese contract manufacturing standards to me. Skimping on components, glue used everywhere in lieu of better quality connectors, general lack of attention to detail. No different to any other piece of cheap tat, except this wasn't cheap.
NAD, gear was usually a bit like spaghetti junction once you removed the cover (wires everywhere, not as bad as most Aiwa cassette decks !), always sounded good, but not well assembled.
Nice tweezers, what brand it is ?
They are Aven AA-SA tweezers.
Sounds like the Teac amp might make for an interesting repair video...
I think it's just a dry joint, but it's quite intermittent so will be difficult to prove a repair. Will probably still check it out though
If it has a speaker protection relay then it could just be dirty relay contacts. A fairly common issue on older amplifiers.
@@howarthcd it's on the Aux line level input only. No clicking and cuts in and out in such a way I was convinced it was my Motu audio interface.
Hey Steve, I tried to contact you on your website but no luck . I always enjoy your videos, especially reviews and products disassembly. I have one favor to ask you though. Could you please 🙏 review and disassemble JBC CLMU ? It would be very appreciated . JBC CLMU is one of a kind. The industry is lacking an automatic tip cleaner with such finish.
I don't have this one, but I can look into getting it.
@@sdgelectronics thank you 🙏 Steve, looking forward to it. You’re the Best.
I think I would bypass the via's regardless the same way you did. Also if using silicone to provide some support for the caps remember to use silicone that's not got acetic acid e.g the natural slow curing version.
I also have the old analogue NAD 3150 amp which has great sound through a pair of B&W speakers.
I'd love to say a pair of Nautilus speakers, but just a pair of 100's i think they are. 😞
I was after some B&W floorstanding speakers (CM9?), never did get them though. All the 2nd hand ones had the tweeters pressed in 😭
@@sdgelectronics I bought mine new to go with the Nad 3150, and a Philips CD player. Some time in the late 80's I think when I bought my first house.
23:36 it's actually a half bridge!
The mod you did there was a very bad ideea! By doing that you disabled the current sense of the OCP corcuit! :) What you should do is change that current sense power rezistors! :)
I'm not sure what you mean? The end result is identical to the original implementation.
I have seen that black glue mess up powered speakers before, and that was years ago. I suspect that it is a planned obsolescence 'feature' at this point. I refuse to believe the designers don't know to not use that stuff by now.
Its cheap glue, so, as usual choose the cheapest option and you'll end up with junk like this.
Why wouldn't you fix the teac and do us all another wonderful video of you doing it?
@@alexandergreenfield91 I will probably fix it, but it also needs a modification to the volume control which is a project on its own!
Hi Steve. Would you do a repair on a small battery charging board/lithium battery pack? Or do not take any work on through here, or would you give me some help? Just you have no contact details on here. If not, no worries. Cheers Rick
9 times out of 10 with that clash amplifire. When it does that when you hit the power and it goes through a cycle and it shuts back off. You have a direct short on the final output of the amplifier 9 times out of 10. It's never the power supwhy. It's always the final output stage of the amplifier. You can save yourself a lot of problems.You go right to that source.You pull the final output?Believe output, stage the power amp.Out and you Check the finals and you would Save yourself a lot of time That brand N a d is notorious Especially that type of amplifier for having The finals going bad It's a good amplifier , but they use lousy finals If I were you , I would not put the same ones in there I would find comparable ones that wouldn't give you the same Output or better at the same voltage And ambridge don't Replace what the same make Do Yourself a Favor and upgrade Spend a few more shekels
Don't know whether it was Hypex or NAD who put the glue on, but it was a terrible thing.
Probably hypex put the black glue, NAD put the brown glue, both were terrible.
Exactly this@@jaro6985
Why would they use that glue? Is this a case of planned obsolescence?
For its low cost.
RTV silicone is more expensive.
Two metcals!
Them hypex modules are terrible ev has started using them in there pa equipment
Well people would be wise to avoid buying these on the second hand market. Using that glue was plain stupid. Board damage has been known for decades now from glue gone conductive. Not having any sort of output protection also is being cheap.
Gen1 UcD is junk, later NCore engineering is a leap in class-d technology.