Audio amplifier repair

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[@walterkeeth5060]

Just because it brought back memories. I fixed an old Sony 5.1 receiver amplifier that the relay got stuck cause someone crossed all of the speaker wires together at once. They got lucky, fusses blew, an only one relay shorted out (got stuck.) Part wasn't made anymore. Took it apart and flipped the lead on to other side, Sanded contact smooth. It fired up. Sounded great

[@Alex-zn8ix]

Am invatat mult de la postarile dvs. Va multumesc.

[@polimorph2023]

I feel these repairing lessons are like stories, if I may. Sure, you can read the first page and the last one, and get what was all about, but the journey is the one that gives you all the fun. Thank you Sorin. ps: more of audio is welcomed!

[@SIXSTRING63]

I ran into the same issue on a rack mounted stereo power amp a few months ago. Symptoms were a bit different but it ended up being a faulty protection relay shutting the amp down when you brought the volume up to a certain level. I thought it was the driver transistors but replacement didn’t help. Had to order a new relay from China but that was the issue. I work mostly on tube gear but try to work on anything to learn. Your videos have taught me a lot of good troubleshooting methods. Thank you for sharing your knowledge Sorin ! I just dig your laid back demeanor. You never get upset or frustrated when most of us would trash it. I am tenacious though, I will keep trying until I get working. The only thing that I threw in the towel on recently was some Peavey class H design power amp/mixer that burned the bridge rectifier on the low power supply of the output, that high and low power supply of that class H was pretty confusing to understand. They only used that design for two years and went with a class D switching power amp. Obviously it had issues and was expensive. I did salvage a nice multi tapped toroidal transformer out of it.

[@jamich1]

Hello from Albania from my Romanian wife Anamaria. I am actually Slovakian living here in Albania. I am big fan of yours too and subscriber (only few days :)). Love how you show your repairs. I wish I was there to learn from you as I am starting with electronics. Id love to do what you do in the near future :) All the best and cant wait for more videos.

[@DumahBrazorf]

The dodgyness meter went out of scale!

[@georgec.richard6430]

hi everyone ,if anyone else wants to learn about electronic repair manuals try Saankramer Electronic Magazine System ( search on google ) ? Ive heard some pretty good things about it and my buddy got excellent success with it.

[@Dr.muthanna]

Nice job Sorin I think it’s a practical solution not a dodgy job Thank you

[@kimspeller5379]

BANG !!!! :) i learnt the hard way about cut out relays ! picked up a marantz pm50 amp from a bootsale with a denon cassette and a graphic all for a fiver !!! one channel wasnt working on the marantz as the relay wasnt clicking, so i shorted it ???.........which then passed DC thru my pioneer speaker !!!!............wont do that again ! lol.

[@bblod4896]

Want to have fun? Insert a couple of 100 microfarad electrolytic capacitors in an UNPOWERED mains socket for your work bench, hidden if possible, don't want to hurt anyone. Ask you co-worker to turn on the bench power. Make sure your standing back. Good job repairing the amp. I repaired many amps years ago, brought back good memories. Thanks.

[@broken1965]

Yes those are input an output speaker terminals the board does the processing those Sansui blue relay are abundant

[@Frank55]

Hahaha! You create a 'dodgy solution' and the conclusion is: "perfect, absolutely perfect!" 🙂

[@tonict2302]

Awesome. Love your videos. PLEASE more videos like this. Repairing subwoofer amplifier. Golden regards...

[@zviruskru]

I watched 'Chernobyl' TV series three times. Its probably the best TV series of all time.

[@MindYourBusiness1970]

As I already wrote on another video I like this new kind of videos (Power supply , Amplifier, Building things)I can't wait for all this new challenges

[@Grinder-one]

"ah, the sound of a working amplifier"...I was dying to see your colleague come up behind you and shout BANG !

[@juanchizabaleta2405]

Congratulations teacher, once again, the ability, knowledge and ingenuity of man; they have triumphed.

[@simeonmihaylov6123]

1:12:00 That's why I watch every video of this channel. Learning, while having a massive fun... Good job, Sorin.

[@wefukthenwo]

Always have some whiskey around for some liquid courage. The bangs are something you never get used to

[@melplishka5978]

That’s crazy. I was super amazed by how the Chernobyl reactor exploded lol. I was 14 when it happened .

[@Zero_Ego]

Absolutely amazing. You are so knowledgeable in the way you can visualise a basic schematic in your mind. That comes only from decades of study, dedication and a solid understanding of electronics. Well done!!! I repaired my first ever switch mode power supply when I did my work experience. It was part of the course at RMIT where students would have to do work experience in a professionally established repair centre. The techs would fix CRT monitors, camera's, computers and more. The day, I said to them "I'm ready and I'm about switch it on to test" one of they technicians went and stood by the buildings mains power meter box - ready to reset the circuit breaker. They were all expecting a huge bang. No bang, no smoke just the joy in knowing that it worked. Challenge successful that day. :)

[@DanielsGameVault]

WOW ! I never thought someone would go as far as to fix a RELAY ! :))))

[@saarike]

Excellent repair and exciting to watch! Thanks

[@electronic7979]

Helpful repair video 👍

[@thulinp]

Nice. I'm all for Mc-Gyvering a relay contact as long as it will run reliably. And I think it will. The relay may last longer with a cover though.

[@jacekwitkowski247]

1:12:18 Is this a toothbrush? YES.... I've felt of the chair... This is so funny.

[@sanderwalberg9026]

Never thought I'll see so much action on this channel, that was more nerve racking than the last James bond movie :D looool

[@neifionn]

I Like all your video's, and notice that you lose a few screws along the way. Time to get a dedicated screw dish to put them in.

[@kidureza2]

Good approach, who would doubt a discrete relay?

[@N3szt0r]

Holy smokes, i can't see what do you did to that relay. Absolutely crazy. This type of relay is very common in upses. Its cheap, about 4-5 bucks, not wearth the risk

[@artineogda]

my eyes are bleeding now. I don't believe he make this

[@CraZyButRich]

read the video description ,

[@will_doherty]

@@CraZyButRich Can you say that you watched the video all the way through, and then believe that? I find Sorin very entertaining - he comes across as a lovely guy, he's obviously got an exceptionally good grasp of how electronic circuits works, and how to make them function again. It's obvious that his employer offers fast cheap(ish?) repairs, and Sorin needs to use the methods that he does to make that work. But would you take any of your devices there to be repaired? Would customers be happy if they saw how their devices have been made to work? I have little experience of carrying out electronic repairs - extensive experience of electro-mechanical repairs though - and some of the repairs shown in many videos make me wince...

[@faizelosman3462]

@@will_doherty if you see what surgeons do to repair the human body, you wouldnt go anywhere near the operating room either lol. And even surgeons need to know their field well enough to make do in a pinch, like in a 3rd world setting, for example. QOS does go a long way, but hands-on fixes with sheer logic and common sense? Priceless, especially for us learners! I've never seen the inside of a relay before, yet after this i will never forget.

[@gerhardpetersen]

@@faizelosman3462 How could you never have seen the inside of a relay? There are many, many relays that have clear covers......

[@parjakobsson2877]

Mono/sub amp often has auto turn on function when voltage at rca input reach a specific level, thats when the relay turn on

[@electronicsrepairschool]

probably u r right

[@PHONE-LAPTOP-REPAIR]

Very interesting to hear story from a board.....this worth a like n thump up..thank sorin job

[@d1bergman]

Very Good, Would you know where I can get a Schematic or service manual for a NEC AV-350E? Thanks

[@worroSfOretsevraH]

Do you know a good reason why I like the video before I hit play?

[@azureuscomputerrepairs]

lol, "let's get someone to power up" :)

[@tanner1985]

It's his birthday today, let's power on! Made me laugh :D

[@josepeixoto3384]

that was another nice entertaining video... that " sound of a working amplifier" he said at the end may have ruined it a bit?; i do not know for sure,i am just an hobbyist,not a pro like he is,, also,no BIAS ajustment there? but i was just reading on a SAE Mark III amplifier "repair hints ",they call it, they have a WARNING not to do that,never to do those thumps; their amps are of extreme bandwidth, they say, and our body being an antenna to RF ,the Amp can easily be ruined by doing that; i have noticed that danger over the years and many Amps, that sound SCARES me... and i seem to have noticed that by the 3rd time,the sound was weaker audio repair is a delicate business,you need a lot of test gear by what i have seen on utube, i am trying to repair a 1998 Yamaha 125+125 watt amp and i know less than 1/10th of what i should know, but i will fix it

[@rduwe9466]

You can not ask 60 ponds for that but for emergency repair it’s nice

[@digihorse6730]

Really interesting. Looking back you actually reproduced the fault when you added only one voltage supply the transistor and resistor got hot as it probably had during the original fault. I must admit I am wondering if it would have been better to source a new relay. Do you think the contacts on the relay maybe not closing at the same time ( assuming different contact distances ) may put a bit of strain on the output pairs. Was that effect over time the original cause of the failure. Time will tell. Nice to think about though.

[@Damjanhd]

that relay is for protecting your house fuse not to go off. Because you have a huge capacitor which makes short for a second and that burn your house fuse. So first resistors power up capacitors and than relay turn on.

[@adrianmircea4474]

Apreciez munca si cunostintele dar nu as face o reparatie de genul, as cumpara un releu nou si l-as inlocui, ma gandesc ca exista un magazin de electronice de la care sa cumpar sau in cel mai rau caz comanda online. Doar ptr urgenta maxima as face asemenea reparatie. Salutari din Romania :)

[@catasebi8744]

Salut Sorin,din ce oras din Romania esti?....Multe salutari din Timisoara...te urmaresc cu mare drag...

[@cachifori]

Hi Sorin good night from Mexico ....

[@emmanueljames113]

sir to be sure the device is not going to explode after working on it u can simply test with diode mode the input (Ac input) for short if it reads mean it definitely going to spark or explode, if it doesn't read you free to turn on the switch😁

[@rohdvestfix]

Hi, can you please tell me what microphone you' re using in your videos. I like how it isolates the background noises. Thank you.

[@sergeaudenaert]

It’s a birthday... on/off....... brilliant :-)

[@christian56311]

I wouldn’t want this guy repairing my electronics. He is an amateur. If you enjoyed this video, watch Mr Carlson’s Lab, Glassslinger or Xraytonyb. These are the Professionals when it comes to electronics troubleshooting and repair. You’re Welcome!

[@fellpower]

Attention!!! You SHOULD say, that the capacitors need to be shortet, to prevent an electrical damage on u, if u touch them.

[@Sezdik]

Well this is a notebook repair store.. so you should expect a repair "solution" like this .. This one was good i like it

[@golubg]

first story in the book is very hard . Great book at all :)

[@kostasvarsamis4155]

common nc/no contacts.. since u found out what was the faulty part, u should had replaced the relay. if the contacts are dirty, u just clean them gently. but other than that u just replace the relay. since the relay is using the NC contacts, means the contacts must be able to handle all the current. means if the contacts are not in perfect condition, they will get hot. getting hot, means melted plastic........

[@weerobot]

Sorin Build's his own Air Cooled Relay...lol

[@lambertax]

Nice vidéo. It would be better for electronics students to know that during soldering, flux is highly toxic on the long term and that it would be a good idea to have a flow of air. Air vacuum, something like that.

[@intrax2tv]

Great Geekax Not the flux this guy uses, it's totally natural! Watch his vbid about it...

[@allelectronicsrepairs7165]

Depending what flux you are using and from where you know it ;) The flux (natural pine rosin) is not toxic at all, however it can carry with the fumes microscopic particles of lead from the solder and any burnt debris from the board (including plastic and any substances accumulated on the board over the time). In any case, you would probably have to do it for some 50 years everyday, for it to kill you. I don't worry about it (I will die way before it ;) from different causes.)

[@kadmaster]

Hello Sorin! Come to Besiktas... We drank alot of radioactive tea in Turkey...Chernobly times....It's just sad.and I need some help for iphone 5s..

[@grumss9248]

LOL... I'm still shaking my head! Still finding great entertainment though- Thankyou

[@Jechanotrix]

The screw missing at 1:03:45 fell of the desk at 16:25 :)

[@paradiseroad8946]

hello bro i have xpria z2 its fall in sea water do u think it will work again?

[@atozramesh4149]

Sir please put the AV receiver trouble shootings if possible

[@martijn4740]

thats a prety nice present

[@amielem]

You should put wreck and repair on the titule

[@baronbarbaron]

:D Dude you should put the relay in to the bin and just put a new one.. They are cheap and this one is may be the most common on the market. I tryed to fix many relays and never work as they should. Once is overheated the mechanical properties on the contacts are gone, and it is easy to stuck again, even with a very small loads. If it work, it is for few times and soon fails again.

[@sonicpk100]

wow humming say what the power this old amplifier nice sorin

[@wisher21uk]

I keep thinking Sorin saying F......d and not stuck lol

[@josuevillasante2546]

apply 24v dc directly to the coil of the relay

[@runthomas]

if you want lots of cheap transformer ....go to scrap yard...and you will buy the scrap transformers by weight...so is like 1 pound for transformer like in that unit....just be careful that they have not been torn to bits by the person who scrapped them...you will definitely find some good one.

[@ilarioschneider2917]

a input serial lamp and no explosion :)

[@runthomas]

why not get a solder sucker 2 pounds on ebay...and most people just use a small container to put screws.....i mean after many years...why are you still losing screws.....its not rocket science to use a small container when disassembling stuff.

[@wattage]

I love when you had Christian power it up. What a fun moment! Hahahah....

[@ferencszabo3504]

Ok, this fix was on McGyver level !

[@NeuronalAxon]

Ooh - that's the book the Chernobyl series was based on - should be good!

[@rty1955]

Those burned resisters should be raised further off the pcb and I would increase thier wattage. Is that relay for in rush current protection. I doubt its for input detection. Mr. Carlsons lab would find the cause of the relay failure and redesign it. Watch his videos!

[@allelectronicsrepairs7165]

Yes, you are right. Mr Carlson would - but again Paul is not in a shopping center repair booth and he doesn't work fast/cheap to survive. I'm sure that Sorin, given time and money for a real solution, would do it, but he is NOT an inventor or radio/amplifier specialist. Sorin is a technician working with what he has available (very little) and fixing things successfully. This is his great ability. Look at Mr Carlson's workshop (or rather a laboratory - like he calls it) and all the fancy and top class equipment he has at his disposal and compare to the (work)SHOP of Sorin. Yet Sorin is very successful.

[@attiqrehman7799]

sir you are gate. i like your videos

[@sonicpk100]

92v cricut worth to check with 100w bulb series. it,s safe

[@rtype4930]

Hi Sorin Magician !

[@errolhibbert2390]

That's repair work for you.

[@MrRvdbeek]

Men long run. Nobody electrocuted 😂blowing up

[@SteveM45]

First,you have a chaotic workbench. Buy a silicon map

[@mcimpoeru]

Buna ziua, Ce sursa aveți pe birou? Va mulțumesc in avans pentru răspuns! Salutari din Germania!

[@SteveM45]

Hey Why do you take the red Strip to gnd?

[@sanjayasaliya1102]

Awesome

[@drssound5273]

Hi frend Watch my channel Good luck 🙏🙏🙏🙏🙏 🔉🔉🔉🔉🔉🔉🔉🔉🔉🔉 🎛️🎛️🎛️🎛️🎛️🎛️🎛️🎛️🎛️🎛️

[@5santim500]

Hello, I have 5.1 surround sound system here is the problem Couple of months ago it stopped working, as in it doesn't amplify the input sound to the speakers. But just yesterday, accidentally I plugged it to 110v source(normal 220v) and it worked, of course there is a buzz sound coming out it(I guess that's because of low power), on 220v it's still not working. What could possibly have gone wrong?

[@isaganibiccay8279]

1:12:20 the sound of a working amplifier..

[@johnrhodes3350]

Nice book 👍 good friend

[@melplishka5978]

Tap on relay too see if it sticks lol

[@tonystr9]

on and booom or not :P lucky guy

[@wisher21uk]

Times like this you wish maplins were still about it would of cost a fortune but it would of been done.....

[@carlos_ruiz_castillo]

Hahahaha poor Christian, sooooo funny

[@grumpyjohntxredneckrc6346]

I Would Of Wrapped 1/2" Piece Of Kaptan Tape Around Relay, Maybe? LOL I Know You Replaced w/New Relay. Butt Great Trouble-Shoot Video! Thanks Teach... PS I Suggest A Magnet On Desk To Hold Screws Soo You Don't Loose Them Anymore? Hmmm... LMAO

[@RAMZEZvideoDesign]

Hi, do you need a trailer, screen saver, design for the channel?

[@rickclink9196]

Like you said the power components aren’t the ones that normally blow. I would start with the power supply and go right to the output transistors. Also many of the electrolytic caps might be of poor quantity or have been exposed to high temperatures. I am 18 minutes in

[@juntech..3440]

replace the Relay

[@kenjunge2768]

Nice work :-)

[@mohamadaldarwish6678]

I like what you did 😍 you repair the relay 👍perfect job. Crazy mind 🚩🚩🚩

[@peterjmcgee4680]

I think where you're making a mistake to your thinking that it is a Mono Amplifier but it is not it is a subwoofer amplifier and you have stereo inputs going into it and it filters out the lows sends the mid-range and highs back out and gives you the Lowe's coming into the box for the subwoofer that's what you're making your mistake you have inputs stereo inputs and stereo outputs coming out just looking at the back of the unit you can tell that right away I have worked on those before and nine times out of ten they get over driven and you nine times out of ten you'll find that there is a resistor on the board that is burnt out and it is in this any power line that supplies the power to the transistors and that's why your main transistors have no power to them because that resistor is burnt out so I suggest that you find a service manual for that unit look up the schematic and find out what the value of that resistor is and replace it and check further down the line to see if there's anything else that shorted that may have caused that resisted a short out like maybe one of the two of those transistors that got over driven that because somebody liked at their base really loud and they drove too much of the audio from the receiver into the subwoofer which a lot of people have a tendency to do they're only filter to receive a certain amount of power into them and when you do too much they do burn out

[@mohamadasriabdulazid4784]

Replace the relay with 3phase contactor with overload rated with 10amp. 😂 If it me I will replace the relay with MOSFET to switch negative side and FET to switch positive side. And use voltage divider to knock down 24 volt to 12 volt for controlling the base pin

[@RichardHeadGaming]

Audio AMP doubles as magic smoke generator.

[@andreavico6198]

"There is no way can be more than an half hour" cit.

[@davidmcniven3543]

Sorin, you lose a lot of screws :) If you don't like the idea of pressing them onto butyl tape on your bench you could cut up a flexible magnetic sign magnet into small pieces. Example ebay item 332945032106. Or cut up an old fridge door magnet into six inch strips. They're very weak magnets but plenty strong enough to keep the screws from rolling around. Thanks for another good video :)

[@emildan772]

Greetings from Romania. Ask your colleague about palinca.

[@ShivYadav-rf1dd]

Aprton madal 1500का डैयोड प्लेट का कंडेंशर का नम्बर भेजें

[@jamesmclaughlinprimitivele4587]

Be back soon the large capacitor was bulgy looking and looked leaky on the tracts, that really didn't melt because it was tired.