I really appreciate this content. Unfortunately this is way beyond my understanding and ability. Trying to find someone like you that has the slightest interest in repairing the old stuff let alone making it cost effective leaves most of us with few alternatives. Much appreciated, entertaining too
@robertakerman35702 жыл бұрын
James Meliti; feel free to review. This is a perfect example/explanation of "basic" electronics. Believe Me when I say "there are very complicated units out there".
@abelabner2 ай бұрын
You sir are very informative as well as entertaining!!!!!
@cat-lw6kq5 жыл бұрын
tha't's got to be the neatest test bench I've ever seen. a real professional at work.
@EirkenElite5 жыл бұрын
Lol I have burn holes everywere on my matt lol don't beer and solder
@cat-lw6kq5 жыл бұрын
I have one of those silicon mats it's safe to drop solder on it, won't burn it.
@joverstreet243 жыл бұрын
Nice repair. May be better than ever with all of those new, modern capacitors.
@EngineeringVignettes5 жыл бұрын
Way back in time, I had a customer bring in an amp where they had tried 4 or 5 fuses to "fix" an amp. By the time they had finished there where blown transistors all the way back to the pre-amp / driver stages. That job was _fun_ Cheers,
@sebo08555 жыл бұрын
Instead of variac, You can use a cool life-hack. Around '80 in Poland, transistors were extremly expencive and hard to get, so You can replace main fuse with light bulb socket, and 100w incandescent bulb, power on, and if bulb just flashed and then glowed a bit, there was no short, but if it was still bright glowing, there was a short. And transistors was saved without nearly unoptainable variac.
@fafb94413 жыл бұрын
Thanks for this suggestion. The light turns on momentarily bright then dims to about 1/2 intensity.
@fafb94413 жыл бұрын
I must add that if the light bulb stays on even at low intensity there is still a problem on the board. I disconnected the left channel output power board because something was burning. When I did my second test without the defective board, the light stays off. Now I will continue and troubleshoot this defective board.
@markanderson80662 жыл бұрын
We've used this for vintage tube radios - when they were new, lol! Great tip. Some make a box with a bulb socket, power cord, and receptacle to plug in the device to be tested. NOTE this ONLY works with incandescent bulbs! Do not use LED bulbs!
@sebo08552 жыл бұрын
@@markanderson8066 Shango066 uses this approach too, and yes, incandescent bulbs is mandatory because they act as high power resistors with soft current limiting due to filament temperature characteristics.
@jamesatkinson64802 жыл бұрын
I used that technique, soldering a 75W incandescent light globe to two insulated wires, and putting it across a blown fuse. I called it an 'economical PTC thermistor'. (PTC - Positive Temperature Co-efficient (of resistance)).
@wagsman9999 Жыл бұрын
Well done. I'm trying to learn basic electronics; theory is one thing... but there's nothing more instructive than watching an expert fix broke stuff.
@don72942 жыл бұрын
WOW! What a fantastic channel. Incredible, detailed, work. Talk about going the extra mile. I have six, 70s-80s-era solid state amps and they each need a little bit of help. Thank you so much.
@trippmoore2 жыл бұрын
I've been watching various vintage electronic repair channels for 4+ years now and only now have I been recommended this video. I love you style and attitude. You aren't grumpy or preachy like some of the older repair guys and seem to be all about having fun. That's what it's all about in the end isn't it? If you aren't having fun then why are you into this hobby? I quit drinking over a year ago (not that I had a problem per se, but it really wasn't benefiting my life in an appreciable way), but seeing you enjoying a glass of wine really sold me. It really conveys the laid back nature of your channel and earned you a new subscriber. The alien skit pushed it over the top and I'm gonna head right to your patreon page and throw some money into your wine and cracker budget. Hopefully it's enough so you can afford to upgrade to a wine, cracker and cheese budget. If you prefer an aged hard cheese or a young runny variety you can't go wrong with a nice manchego or brie, respectively.
@georgecrosscross82532 ай бұрын
Happy comments, totally agreed!
@trippmoore2 ай бұрын
@@georgecrosscross8253 glad you replied after a year. lol. I think I was never recommended another of your videos even though I subbed and I completely forgot about it until now.
@franciscorompana29855 жыл бұрын
I have so much fun watching your repairs. Comments are fantastic, it's like reading the pages of a magazine. I learn a lot with the vintage HiFi. And they are beautiful also. No plastic. Amazing.
@AhmedAli-fr5yt6 ай бұрын
Beautiful bringing the devices into life again, this is an art.
@j.fanning81582 жыл бұрын
Wow ! Nice going with the very detailed step by step diagnosis and repair of the stereo amp. Your attention to detail is impressive. You are definitely a pro at this high skill electronic repair. Thanks for sharing this quality demonstration for others to learn from and enjoy on KZfaq.
@allenh1184 жыл бұрын
In addition to a variac, my grandfather taught me to use a 200w light bulb wired in series with an outlet. A short in the unit on the bench wont blow fuses or "let the smoke out"... it just lights the bulb.
@fafb94413 жыл бұрын
Thanks for the variac suggestion
@thefilthygringo92282 жыл бұрын
I love watching your videos, I have absolutely no clue what you’re talking about because I am not that technical but for some reason I just like to learn. Not like I will ever use this information but it’s just fun to watch. I like watching you get in there and soldering putting components into boards. The grunt work you know what I mean
@isaack1050 Жыл бұрын
I appreciate people like you sharing your knowledge. It is so rare to find anyone that can repair solid state electronics, I've resorted to working on my own. Thanks for your help in turning an industrial controls guy into a 1/4 funtioning solid state repairman. I've got a Sansui G8000 I want to hear before 2 years... I may kick the bucket before then .
@raymond37224 жыл бұрын
Time and patience is what shown here and very professional 👍
@DaveGVideo5 жыл бұрын
Good catch on the diodes. Also, very good point on checking further into the driver circuit. I’ve repaired a couple of amps that had collateral damage like that.
@MrRockydee073 жыл бұрын
Wow this a clean looking and laid out unit , My Fisher TX500 receiver is full of wires soldered everywhere.
@drwisdom14 жыл бұрын
I like Mr. D-lab's attitude and presentation style.
@billy.goumenos2 жыл бұрын
I checked the dictionary for the word ''professional'' and I saw your picture.
@Steve-bo6ht5 жыл бұрын
Absolutely hooked on these how to identify problem solve and repair audio equipment, and going about it the correct way by being safe and showing what test gear is needed
@BenState2 жыл бұрын
also check out Mr Carlsons lab
@transwave504 жыл бұрын
I was doing Amp repair back in the day we were quite busy at times surprised that quite alot of people looking at these repair vids these days
@Graybeard_2 жыл бұрын
Wow I have an old JVC boombox (RV-NB20B). This was my outside source of music for more than 10 years. I loved it and bragged about how tough it was and how good it sounded. It quit working about 7 years ago. When I turn it on, the red power light comes on for a second and then there is a static pop from the speakers, and it shuts down. I have kept it with me always hoping I would come across a proper electrician who could fix it. I wish your were close by. I bet you could fix it. I'm old enough to remember when most towns had a shop where you could bring your electronics to be repaired. Now-a-days folks just throw the unit out and get another one.
@dell1773 жыл бұрын
I broke down and bought myself a vacuum desoldering gun on sale a while back, it wasn't cheap but it saves a ton of time replacing parts on these old units.
@tomislavukraden41512 жыл бұрын
Your technical knowledge is inversely proportional to your sense of humor. Stick to what you're good at. ;-) Thanks for the tips. I wish you all the best.
@johnhricko82122 жыл бұрын
Well done! I bought a used Marantz 1030 in the seventies... loved it!
@MrChrisRP3 жыл бұрын
Very cool, D-lab. Moment I saw the burned resistor, I thought exactly all like you. Thanks for taking it home in the video.
@abelincoln955 жыл бұрын
Another "save" in the column!! Wish I had the benefit of this knowledge 10 years ago. I bought a Sony receiver/amp in 1980 when I was 18. A very good unit. It finally bugged out on me & all the options to repair it were so obscenely expensive at the time. It met the trash heap.I still look for something close to replace it with. Thanks, Terry!!!
@jackjohnson99895 жыл бұрын
The 70's and 80's amps are super but man, the 70's and 80's guitar notes......just awesome! PS:- Electronic repair instruction wasn't too bad either.
@vinylcabasse2 жыл бұрын
this is awesome info. i wish i'd watched this before jumping straight into swapping my main transistor pair. i didn't realize it was fine to check for component shorts with the components still soldered onto the board. thanks again
@SRajputana248 Жыл бұрын
You are the best repair electronic engineer. I was the hobbiest electronic person.
@henri-laurentchezeaud14842 жыл бұрын
Yes electronicians can be fun too. Keep on old man¡
@mrmustangman Жыл бұрын
i have no idea what you are talking about or doing but i still find it very fascinating.!!!! 👍
@luisurias97395 жыл бұрын
Excellent!! Thanks for your shared precise knowledge!
@f.k.burnham84915 жыл бұрын
I am totally impressed! Another tech who actually knows how to test components, and not use "universal" replacements. I use the 105C caps wherever I can in my repairs. They just seem to have a longer life. OEM semis all the way, if at all possible, especially on Sony products. Did you check the bias pot for opens or shorts before firing it up? I have found a number of times that bias pot is fried. I also check any bias diodes, transistors and resistors. Over the years I found that in the DC coupled amps, I replace the drivers as S.O.P. I normally clean off all the old heatsink compound as sometimes it gets pretty hard. The old clear compound often took a chisel to remove if the part had really overheated. Great video and explanation. You got a new subscriber. Thanks.
@generalcurtis3lemay1804 жыл бұрын
2SD371 finals are a TO3 package so the heatsink thermal compound doesn't go on the metal, there's a vintage mica or recent cloth washer between them. All the old thermal goop needs removed. The old filter cap is 70 volts and D-lab puts in an 80 volt. It could be D-Lab's know-how is 'monkey see, monkey do'. There are different types of snap-in caps and some take more current than others. Should we trust D-Lab with vintage audio? He's no expert, might be military radio trained. 🤠
@wedoshotz66454 жыл бұрын
@@generalcurtis3lemay180 All e-caps are rated by value & voltage, along with thermal tolerance.......nothing related to current. It's SOP to put in an equal value replacement with a little higher voltage rating. As a matter of practice, unless I'm using sil-pads, I clean all surfaces & re-apply fresh thermal compound to both sides of the mica insulator. But in a lesser powered unit with an ample heat sink like this, it could be excused.
@brianr9872 жыл бұрын
Sounds good! Nice to see some solid state audio here, most electronics are tube oriented.
@bigdumbguy Жыл бұрын
Thank you for getting me started.
@CrashCarson142 жыл бұрын
Pretty cool way to understand fundamentals
@rel3752 жыл бұрын
Extremely good job. Congrats Sir.👏👏👏👌👌👌
@gandichild2 жыл бұрын
Excellent video Terry
@fourty5mag2 жыл бұрын
I should have been doing this my entire life! Now I'm at the end and not enough time to get back in it! Good job!
@windward28182 жыл бұрын
Transformers also age, and may exhibit AC leakage current to the case. If the unit does not have a ground (3-Prong plug) you could temporally attach one to the chassis (or any piece of case metal an operator may touch) if at ground potential and not a hot chassis. It is fortunate that D-Lab uses 115VAC at 60Hz power, in that you can make a simple AC leakage detector by using a GFCI as part of your isolated AC power supply. By supporting both a regular and GFCI receptacle, after repair and setting the AC voltage at high line, you can use the GFCI to see if the repaired device has AC leakage to the case above 5mA. If so, the GFCI will trip. To measure smaller leakage currents you will need to use a sensitive AC current leakage meter. All "appliances" should be checked for AC leakage before return to service. Traditionally this was targeted at AC motor powered devices with issues with motor insulation breakdown. However, as transformers age they will also exhibit insulation breakdown. You could HiPot test the transformer to understand a withstand voltage, or possible problems due to insulation breakdown. But, I think the leakage test is probably sufficient and quickest for most repairs. I would like to hear about if others test for AC leakage. Using a GFCI receptacle is a rather quick solution especially if apart of an AC variable isolated power supply. If replacing a transformer with a new unit you could HiPot test, although this test is usually done at the factory.
@1o1carolina53 Жыл бұрын
Love your channel came here from Amp Repair Guy channel
@cassandraarnold74393 жыл бұрын
this is SOOO great! thanks much for posting, great info.
@lwilton5 жыл бұрын
Boy, you were lucky. I don't think I've ever gone thru an integrated amp of that era with blown outputs that didn't also take out the phase splitter or driver transistors.
@saddle19404 жыл бұрын
And used an out of manufacture STK module!
@jeremy-ue2ew2 жыл бұрын
thanks for sharing your knowledge i appreciate a good teacher also like how you dealt with the troll.
@HobbyOrganist Жыл бұрын
I have a Realistic STA-85 I bought new in 1978! It's powered wall speakers on every computer Ive had since 1994 until about 3-4 years ago when it started periodically making noise like static maybe and I could see the bulbs inside kind of flicker at the same time. So I looked and didnt see anything obviously burned or wrong and bought a new amp/receiver. Still would like to fix the old STA-85 since it has mechanical switches and my computers and amp etc are all in the basement on a rack and I turn the power off to the amp, printer and monitor with a wall switch at night and when at work (computers, modem, router run 24-7) with the STA-85 this worked perfectly with the new one and its electronic controls, turning the power off means after I turn the power back on I have to go downstairs and turn the amp on and set the volume level every time. I figured on replacing the caps regardless of how they looked as they ARE from 1978 and see if that fixes the issue, havent done it yet, but it worked fine, powered up fine always, never blew a fuse, just that periodic noise over the speakers.
@larrydering15984 жыл бұрын
Very good repair and instructions. Thanks for posting this Terry.
@justsumguy2u5 жыл бұрын
I'm glad to see you tested all of the transistors. I've seen many shorted driver transistors take out the finals
@sonlyme44454 жыл бұрын
Thank you for such a comprehensive and clear explanation. And kudos for the mini movie troll abduction.
@GregsGarage5 жыл бұрын
Cool to see a solid state repair. It makes sense that the caps work just like a tube amp, but I'd never seen one described like that. Thanks for bringing us along on this one.
@Rover2113 жыл бұрын
Brilliant! I enjoyed that - tools for the job!
@172Break2 жыл бұрын
My new fav channel! Glad I found it.
@williamjones4483 Жыл бұрын
Back in the day bad i.e.; shorted power transistors figured heavily in blowing fuse issues. People would do all kinds of bad stuff to the outputs, including but not limited to, shorting out the speaker terminals. This actually an easy fix. Burned components made themselves known.
@smstiao-tecnologia5 жыл бұрын
Yeeeehhh man Realistic is live one more time!!!!! Good repair Tery!
@midmodaudio65763 жыл бұрын
Great video, thank you!
@upupandaway5646 Жыл бұрын
Great choice realistic are way undervalued. 👌. Thank you very much for your knowledge 🙏
@Dan79istheman5 жыл бұрын
Nice one Terry. I actually thought you were playing The Who’s - Behind Blue Eyes in the test. I love these 70’s and 80’s amps. Appreciate all your tips
@bigmac9655 жыл бұрын
Sounded like Emerson, Lake, and Palmer to me. I need one of those royalty-free CDs.
@JayanthookDass8 ай бұрын
You are great Terry. Thank you very much for this informative video!
@macgvrs5 жыл бұрын
Very helpful info, especially about checking the power supply diodes. I might have had to learn about that one the hard way. Nice sounding little amp.
@bautistaconcon57195 жыл бұрын
Hi teacher very very nice interesting, your age same my father I love it & I love your video too I got more technic in trouble shooting amps,but don't forget your wine really refresh your mind, thank you for the video too. More power & God bless.
@mellewallen4832 Жыл бұрын
Love all the comments and experience you bring to the channel . I am glad to see the transistor amps and recievers ..
@JohnLee-mq4hk2 жыл бұрын
They are really good sounding amplifiers.
@Qban2205 жыл бұрын
The other neat little trick if you don't have a variac is to replace mains fuse with 60W or higher, regular light bulb. If your amp has no shorts, light bulb should flash and then dim after power is applied. If it keeps bright constantly, you have a short in the circuit. Light bulb will protect the circuit and take the energy away from the short so you will not be burning components if the short remains. Mind you it has to be an old type regular, plain light bulb. No led, energy saving fluorescent or other rubbish.
@darinb.32732 жыл бұрын
That would work fine if the fuse is off the main voltage, the same idea can be used if the fuse is on the lower voltage(s) most cases a 12 volt bulb would we work just fine. You could even use a tail light. That is a brake/turn and parking light bulb. That gives a choice of two current limits.
@peterschmidt99422 жыл бұрын
That's what I generally do when I'm hooking up something of unknown condition. Saved me many a time before the smoke got out and couldn't repair it LOL.
@JamesE7072 жыл бұрын
Great video Terry. You put a lot of work into these!
@mathiastollefsen3 жыл бұрын
I'm trying to fix up my Sansui Au-717.. this helped a lot!
@goodun60815 жыл бұрын
At 9:00, an analog ohmmeter will check the transistor junctions, even *in circuit*, typically giving a reading of about 10 to 20 ohms between base and emitter, and base and collector. Short circuits are typically to be found between the emitter and collector. I didn't watch the whole video yet, but it bears mentioning, in case Terry doesn't, that if there is a polarized electrolytic capacitor used as a feedback capacitor for the differential amplifier input circuit, it should be changed to a bipolar capacitor. Sometimes those feedback caps get hit with a backward voltage surge as the power supplies are energized or depleted , leading to a damaged or, eventually, blown cap . An electrolytic bipolar cap is fine; or at the very least put a small film cap across it. I'm surprised this unit doesn't have a removable bottom panel, most units of its era did and do.
@chrisc9406 Жыл бұрын
An enjoyable watch. Thanks for posting.
@waynethompson84164 жыл бұрын
Dang! Really blew a lot of stuff on that one. Good thing it was sent to you to repair! Changing those caps was a very wise thing to do. Keep up the excellent work Professor!
@greggaieck48082 жыл бұрын
D lab Electronics your CD player is so awesome
@robertlandry89195 жыл бұрын
Great job. Like that you accept the challenges!!
@cranegantry868 Жыл бұрын
Very efficient repair!
@pumpdumpster5 жыл бұрын
Hi Terry, thanks for sharing your vast knowledge!
@Pyridox5 жыл бұрын
Nice repair, very thorough. I know what you mean about using generic replacement transistors, sometimes they don't work properly, I've experienced that in the past. It is best to use exact replacements whenever possible.
@CraftyZA4 жыл бұрын
Good video. One extra step that I usually do. But you need a 2 channel scope for this. Juxtapose the 2 channels over each other and check the bias. Sometimes it is needed to tweak a little bit to make sure they are the same.
@jimsuber6784 Жыл бұрын
This was a great and very detailed video.
@tschupbach Жыл бұрын
Nice. Every time I try to check final transistor temperature, I remember (a split second to late) there is voltage there. On a 70 volt rail, that's 140 volts across.. OOPSIE Now I use a temperature gun (non contact) to check. Works well on tube envelopes also.
@THOMMGB5 жыл бұрын
Thanks for all the repair/troubleshooting detail. That was really helpful. I learned a lot. I've got a Pioneer VSX-920 Audio Video amplifier from 2010 that has issues. A neighbor was going to throw it out. Hopefully, I can solve the DC 003 error code problem and get it going again. Regards, Tom
@Euthymia2 жыл бұрын
Probably already done it by now, but any electronics made in Asia between 2005-2007 (basically everything) is likely to have classic "cap cooties" issue. The Asian cap manufacturers got a bad recipe for electrolytic that lowered the life of the caps they made. Millions of them. Whenever you see a TV or monitor from that era that powers on for 5 seconds and shuts off, it's those caps. $10 fix in parts.
@taylorfusion4 жыл бұрын
Learning so much and your explanations are really lucid. Thank you
@johnbedell23762 жыл бұрын
Great video. Very informative. Looking forward to more. Thank you for doing this!
@terrysamaroo90912 жыл бұрын
Very good troubleshooting step by step!
@Tasi78 Жыл бұрын
Is that you Mr. White?! 😁Walter White😎 Great video, thank you!🙋
@josephwood4992 жыл бұрын
Terry looks like a clone of my late grandfather . Wow!
@chefbink615 жыл бұрын
WOW a old Beckman DDM!!!! Haven't seen one of those in years!!
@d-labelectronics5 жыл бұрын
Yep, I love the vintage Beckman's with the rotary select switch
@cdavidhord4 жыл бұрын
I loved this video-very informative, funny as well. Great job!
@AlexIsASeraphim2 жыл бұрын
Awesome. Thank you, I really appreviated this. Going to share this video with a friend. B.
@TABE-O Жыл бұрын
Good work D labby !
@listerine-pr5lt5 жыл бұрын
Its an Entertaining clip and you set a puppet show.
@oscarpeddiford7168 Жыл бұрын
Thank you for producing this video! ! Love it. I am learning to be a sound tech repair.
@tottimejdi58202 жыл бұрын
clean and perfect work
@madmanmechanic8847 Жыл бұрын
A quick way to diagnose any shorts in the system is get some tin foil the thick gauge is recommended wrap it around the fuse. Then install, plug in the unit and push the power button all you have to do is follow the smoke . No test equipment is needed .
@MikeY-hl5pi5 жыл бұрын
Nice video as usual! Thanks for sharing!
@paididoy4 жыл бұрын
Very detailed explanations. Great video!
@windward28182 жыл бұрын
There are options today for "better" components which will easily surpass older designed semiconductors and Electrolytic Capacitors. Now can you get them the same package, lead space and diameter through-hole configuration, well that could be a challenge.
@brucknerian9664 Жыл бұрын
I have to say much thanks for your repair videos, one of the best if not the best.
@edwardallan1972 жыл бұрын
Very educational fun. Thanks!
@PROJECT_936_dot_NET3 жыл бұрын
Exceptional job You have inspired me to work on my channel, thanks. 🐼
@TamerRagheb Жыл бұрын
Oh meeeee.. such a great work "D", I wish I could ship my Akai intigrated Amp to you to fix it. My kids blew one channel side. I don't know how, but this is what happened.
@dr.parthasarathiroy1989 Жыл бұрын
Very much informative... learnt a lot.. thanks..
@mioryderoncgnp15893 жыл бұрын
nice job, keeping that Realistic out of our land fill.