Hello Mark! Silver plating the power switch contacts, after perfectly recreating dome shaped surfaces on both contacts... I have not seen anyone on RU-vid ever go through that much fine, precision work to restore a vintage power switch! You are clearly in a league of your own. Beautiful attention paid to every detail, to the point that you even consider the next repair person, when reattaching component leads speaks volumes to your ethic as well. I love your work. I am so happy that I found your channel. Please keep it up as this is really great stuff! Thank you for showing all of us how it should be done proper! Fred
There's a lot of great content being created like this channel i have a few other repair channels i like to watch while i'm waiting for new content to be released. I probably waste to much time watching all these channels lol.
Awesome work mark, going that deep to clean the switches was a great show of dedication. In order to overcome the flickering lights once switching to led I build a small rectifier using 1N4001 diodes, dropping resistor if necessary and filtering capacitor (maybe 470 uF -1000 uF for those three lights). Hasn’t failed me yet. That regulator mod is a brilliant one.
Your knowledge has become a rare thing these days - which I think is worrisome - but a sight to behold. Absolutely brilliant, please keep teaching this knowledge. Absolutely brilliant!
Oh, what a joy to watch 👍 Learned a lot too… After watching 3-4 videos with Mark, this channel has gone straight to the top of my viewing list… 338k subs would have been more fitting… He might pass the 100k mark sooner than we think though… All the best from Denmark, Per.
I worked in a dept. store and sold a TON of these receivers...and the bigger siblings as well. They were quite good for the money and super attractive designs.
Most impressive operation so far. Can't believe you plunged into murky waters so willingly and surmounted the many surprises in this operation. Great video 👍
Hey Mark you are genius, & I do share those to my brother in India & my friends too though we are not technicians but love the way you always smile & laugh while enjoying your work to the maximum. Cheers !!!
Enjoy seeing your subtle smile and laugh when you work, also heard a slight whistle too. Doesn't take much to make me happy, your work does that to me.
@@HansDelbruck53 You’re kidding right? This man is every bit an electronics engineer and then some. Many elements of what you see might be classed as technicians work, but I can assure you he is way more than that. Analogue, RF, digital and many more design skills are demonstrated in his videos. And I by no means belittle the name of technician here either, as that is a deeply skilled class. But to have the knowledge demonstrated by Mark there are many years of varied design work gone into achieving that.
I've just found your channel too. Mostly I have no idea what Im looking at or you're talking about, However I love this Channel. You would definitely be my Go-To man if ever I needed any Hi-Fi fixing. You explain and show things very clearly. Fascinating! Keep up the great work. I think you are a dying breed in this modern throw-away world. 5*
Half of the time I haven't a clue as to what you are doing or talking about, I still applaud when the toast pops up out of the toaster 😉. Mesmerising stuff and a bloody genius at work.
I love the rock solid feel of these units from that era. Great video and skill beyond what I was expecting to see, and the plating, and microscope view wowzers.
Watching your videos brought back memories of a couple of repairs I did (had been putting off) on both my 1980 vintage stereo components. First was the balance pot on my Sansui receiver, I had tried spray electronics cleaner but that didn't work as I could actually feel something inside had worn. I sourced a used pot online and installed it, success. The other was my Technics SL1600MKII turntable, it would power up but nothing else would happen. On disassembly I discovered the remnants of (IIRC) 2 belts that operated the tonearm functions. I sourced new belts in the form of correct sized "O" rings, again success and now my stereo once again rocks as it should. I still have one "lost cause" in the form of a Marantz SD8020 Compudeck, it never worked correctly with Marantz techs claiming they could find no faults with it
Nice recondition. You don't see anyone on youtube go to the trouble of replating contacts. The resistance test when you finished it was interesting. Might of been revealing if you got a before and after test when you polished them. The cyanide bit sounded odd. I think going by the net, it's used to liquefy the silver. You learn something new everyday. Thanks for another great video : )
I had a receiver that looked just like that. In face, I can't spot any differences, although I don't remember the model nmber. My dad bought it at a garage sale for $5 in about 1983. It had apparently been dropped onto the front. Wasn't too bad, but it slightly bent the tuning knob shaft. I made a couple of repairs inside also, to the switches/pots. I don't recall the exact damage, but it did work pretty well. I took it to university and beyond. I do specifically remember, though, that even the original incandescent bulbs would pulse with the music. You're correct, it wasn't as sharp as those LED bulbs, but it was still there. It was an apparent "design feature." Love the videos!
Those switch contacts remind me of the ignition coil points in the distributor of older vehicles, regular filing of those contacts and dwell angle gap to keep the ignition system functioning at peak. Those were the dayz, thankfully now hall-effect sensors did away with that menace, but created a whole new set of issues lol.
I had one of these or a model dang similar. It was in my room all through my teen years up until the time I got married. Scrapped it maybe 10 years ago for parts.
Japanese HiFi was as much about the mechanical build and materials as they were about the electronic design. A repair worthy of the original philosophy of ‘built to last’. I noticed that the bearing support bracket/strap on the power switch was omitted during reassembly.
Good Job. Congratulations|! Years ago i repaired a Yamaha amplifier. It had the lamps series- connected and powered by a constant current circuit, which drove me crazy. A spare lamp was not available, so I replaced all lamps with LEDs.
Danke für deine schönen Reparatur Videos! Ich verstehe deine Sprache leider nicht aber ich weis auf was du hinaus willst. Reparaturen mache ich auch aber deine Profi Ausrüstung hab ich leider nicht. Außerdem kann ich nur mit 8 Fingern arbeiten weil meine linke Hand teilweise gelähmt ist. Aber wie gesagt: Wir lassen uns nicht die Wurst vom Brot nehmen! MfG Mattze!
Hi Mark. You did exactly what I might have done. Fitted the 7810 without recommended stability capacitors. Being a radio it might matter. Well done as usual. This used to be my job. The EMI pick up was fascinating. My 1970s Sony tuner hates CD players. Simple fix, switch the CD off.
Такой отличный канал с таким качественным контентом и так мало подписчиков. Вероятно что он не рекламирует себя и в этом есть причина. Один из немногих профессиональных ремонтников которых можно смотреть с удовольствием. Браво мастер
Very ambitious. However, going to this extent to clean switches makes sense if this is a hobby and you don't have to make a living doing this. I've worked on these receivers for years and never needed to do any more than schpritz the wafer switches with Deox to obtain a good result. As for the push switches, drilling a very small hole with a pin vise allows access to spray Deox in them for great results. As for the power switch, you can still find parts like this on the web. Again, all that works if this just a fun hobby. Nice work.
Did you forget to place back lever at mains switch? It looks like its missing so those screws dont stress plastic much. Great vids btw, many thnx for sharing.
Great work! Maybe I missed something, but I'm very surprised that you didn't replace all the electrolytic capacitors and do a full adjustment according to the service manual. This is absolutely necessary in such old devices.
You know some old electrolytics are actually in really good shape - sometimes even better spec than new miniaturised stuff? 😀 Only replace if they test bad or show physical signs of a problem like electrolyte leakage. 🙃
EM pinball machine contacts are made to last you could easily cut off switch contacts and solder them to where you need some I'm now hoping my QX949 has developed a faulty mains switch, went in box fully working, came out years later and won't even power up.
carefully made,quality ideo. stereo microscope.....class :-)impressive build quality by Pioneer...but not n league where makersincorporated good spark snuffers. you have a long way to go, Mark....a young guy, just to get UT hits, please don't use vicious chemicals - prefer to have you arund, eh? my achoolpal, Alex, electronics whizz, took som big voltages, developed MS, did'nt live to see 22, we can't always be repaired, like the Pioneer. sermon over. you and Techmoan aebest things on YT.all the best.
No capacitors on the 78 series regulator? Maybe the one you used had them built in? Lovely repair though. I really liked the plating process. I used to work for an ASC 25 years ago and we just replaced broken with new I guess you have to repair parts if you can't get them.
At 26:09, you forgot to put the support plate back on that spans the two binding posts. It is designed to distribute the clamping force of the two nuts across the housing's length to support the rotating cam inside the housing. What happened to it? You can see the plate I am speaking of beginning at 12:27
If ya'll added a drop of gold where you sandpapered the contact it might possibly have been better than silver. In our big electrical contacts at work it was always silver. My guess is if gold little filching fingers would have occured.
Once again excellent work, but tell me why you didn't check the AUX phono sockets where they connect to a PCB for dry or cracked joints before anything else?
I've got exactly the same receiver powering a couple of Advent 3 bookshelf speakers by Henry Kloss. Beautiful little setup, but I have a problem with my phono input "falling out". Will try to solder up the joints and maybe change some capacitors. Not sure if the last is worthwile. It could be the record player, an SL1210. Found a video where you did some repair on one so my thought it is might be the wiring in it.
swap the turntable wires around on the receiver and see if the phono channel fading out is the same as before or the other side, that will determine what is at fault
39:25 Why not simply connect a capacitor in parallel with the LEDs, and an additional diode to rectify and then smooth out transients? If its large enough, at least it will be a smooth dimming effect rather than the jarring 'disco' effect. Edit: Commented too early! Just finished the video, seems you fixed it in a similar way!
Any help on Teac AG V1200 rear channel not working front all good. No schematic noticed relays on power board are any used for the audio surround sound portion?
I got a Denon 900v it has one channel that is weak and distorted do u have any common things to check on these am gonna start tracing it out soon so just seeing if you know any common troubles with these. A fabulous receiver when it's working.
I have a similar Pioneer amp that my local repair shop couldn't fix. Input voltage supply is what it should be, but other voltages are low. Could it have a weak transformer too?
Could you describe test setup for amplifier test setup with schema (Dummy load setup) also setting FM AF transformer setup princples also how connect analyser etc?
Hello Mark. Nice to see your your excellent electronic skills but you repair on the main switch will last as long as it did from new. If you plated the contacts with platinum that would have lasted much longer, platinum has a melting point of 1,774 deg C. years ago they used platinum contact tips for the contact breaker in cars and m/cycles I don't know if they still do now. John
Hello there ! I've been watching Your videos almost a whole day :) Great channel , must admit .I have a question , rather request, for You : I'd like to buy a really good quality stereo amp with phono section (used one) but my budget is "thin" . However what would You recommend me to look after? Thanks in advance and best regards from Serbia !
Good man, I knew you could fix it. Did you ever use two silver spoons to get stubborn knobs off a silver plate of a receiver. wedge spoons at 9 and 3 and pry off knob, no scratches to face plate.
Polishing and plating the contacts won't last for long. A real snubber (cap and resistor in series) will dampen the arc somewhat. If you really want to save the power switch install a buffering relay. It will take the surge and the power switch then only has to energize the relay coil. Done it many times and have had no callbacks.
hey mark, can you work on my denon 2802? it has not sound coming out he speakers. the unit turns on but the sound relay don't kick on for sound to come out. can you fix this?
very nice restoration which I thoroughly enjoyed! One question: I was expecting some switch lubricant - one of those which leaves a protective coating behind - on all those switches? Amazing video thanks!
So…just spitballing here: Is it possible that the main reservoir caps are not at spec anymore? Or if they are that raising their capacitance value may help the transformer not work as hard? I have an SX-727 that needs all of this done but since I can’t pay myself to work on it it sits in pieces in my shop.
