Another Pioneer SX-737! Why won't the relay click in?

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In this video, I figure out why there is no sound out of this receiver. With these vintage stereos, sometimes the protection circuit may appear to be doing its job, but it might be faulty itself! This is what happened with this particular unit. In this video, I show how I found the issue and what I did to solve it.

[@marktubeie07]

It's because you show all the 'warts and all' issues with your repairs, including where you may guess wrong, that I enjoy them so much. Learning how to diagnose is what it's all about. Looking forward to more pal, nice one!

[@MichaelYates]

Thanks for yet again a very informative video. These vintage Amps and Receivers bring back some great memories for people as well sound great and look cool that's why they want them back nowadays.

[@dastinger111]

Always eager to see a new video from you. Your relaxed style fixing these and not being afraid of showing everything is what makes it really interesting! Thank you!

[@roberttaylor5764]

I worked in a Pioneer factory service shop and Pioneer would supply us complete Power Amplifier boards to replace under warranty on customers units. The reason the transistors would blow was bad bias pots the wipers would lose contact on the tracks when the receivers would get hot. I just rebuilt one for a friend recently and it was nearly 50 years old, replaced lots of electrolytic to get it back working!

[@RalphRacc00N]

recently fixed a SA-900 and it was doing all kinds of wacky things till I found out the wiper was dead in the 50ohm pot. strangely at the time there was NOS power amplifier boards on ebay. seller claimed to be a service tech for Pioneer in the 70s and and 10+ for sale.

[@jorgeenriquearagonquimbayo9397]

Excelente análisis del circuito de protección. Donde puedo hallas el esquema y sus transitores originales. Resulta que han cambiado los tansistores. Y la verdad no pu4edo hallar el esquema de protección DEL PIONNER SX 737

[@v12alpine]

I have an SX1000 that "works" but needs some help. Not looking forward to the spighetti mess.

[@parkersgarage4216]

whats a fair price for these? i came across one locally guy wants 160 for and it was just serviced and had some things replaced. lets pretend nothing was replaced on it what should someone pay? another question would be are these any good? i see they only have 35w per channel which isnt much. does that limit its performance? should i go after a higher model than this? i know nothing about these older recievers so any help is appreciated. i find your vids interesting because when i do get one i can fix anything on it easily.

[@Poppinwheeeeellllllieeeeez]

Wow they sold a lot of those sx-737 in your neck of the woods. Disappointed you didn't pressure wash the controls. Because it only takes a few mins, I always clean and inspect the unit and then clean switches and controls before doing anything else.

[@JImmY1982MinG]

I wish you live in Texas. I got a few pieces of these vintage gears that I think you'll love to make videos on.

[@BODEMAN85]

Great video. My sx-939 just started going into protection randomly. Now it just stays there lol. Called my guy that I would take the reciever to for repairs but he's no longer doing that so I got referred to another guy. Nbd but I think its time to start doing this myself, your info is very helpful keep up the good work!

[@quad1000]

Are these SX-X3X receivers worth restoring? I have a 737 myself, my buddy has a 636. Both nice cosmetic shape.

[@tee-jaythestereo-bargainph2120]

i am really digging the channel keeo up the great work !! do you live close to Kentucky ? i wanted to get my Sansui G8000 preamp board recapped . love my G8000 2nd biggest reciever ever made by Sansui it has a rich powerful sound density but 56 pounds 😥

[@KolfMAKER]

Great diagnostics, very learn full!

[@JoshuaWShanks]

Do you keep a certain assortment of caps on hand? If so, how do you determine what to keep on hand?

[@AHFixIt]

Check out these videos: kzbin.info/www/bejne/r6moZKCJi7Rgo68 kzbin.info/www/bejne/pmrGg5xvbtiAY8k

[@classic287]

Nice job. I wish I knew how to fix those things. I have a ton of amps, receivers and record players.

[@louvendran7273]

Had one of those. Still might be in my granddad's house. Bought in about 1975.

[@dicktomasko1553]

Hi I have an sx1010 that has a loud pop not volume controlled enough to blow a small speaker....Best place to get caps? Great video by the way.

[@chrisd5299]

Really enjoy your videos, especially you’re willingness to admit your mistakes and let us laugh along with you.

[@idiamin6311]

Super Video ....vielen Dank und liebe Grüsse from switzerland.......🍻😍

[@neccron9956]

I would suggest to put a snubber diode across the protection relay, this can help protect Q7 when you power off the receiver.

[@mumbles552]

One question. I just picked up a Zenith MC 7050 which is very similar visually and under the hood to certain Pioneer models of this era but it has one issue. The lights come on, FM tuning needle sweeps but there is no sound out of speakers. Power supply and output transistors test good as do all fuses but the protection relay doesn't click at all. It's almost as if it is stuck in protection. Any idea where to start checking this? Thanks!

[@8757nike]

I bought a Marantz 2230 18 days ago it’s been working fine, I love this thing, but lately I’ve been getting this static on the inputs for the speakers. I try switching the input to auxiliary/tape/phono Still get the static crackling sound through all my channels. Can you help?

[@hectorcesar67]

Thats the exact issue I have with my SX737, no audio comes out, I just dont know nothing bout electronic and I don't know how to choose the right person to fix it Any suggestions? Thank you all!

[@madmanmechanic8847]

I found you channel by accident and really enjoy them very well laid out and you have excellent video editing skills. Can you do me a favor ? There are thousands of royalty free music out there your song you run all the time was great for the first three videos but now it getting very repetitive I am now turning down the audio when your repeat music is playing. How about thinking out of the box and change your music up and live on the edge. Other than the music you play over and over and burn out I love your videos! I am studying electronics I have one of the old Radio Shack kits but I have a lot to learn I to have a Pioneer SX 424 I think is the model I am going to tear apart and learn its myu first test dummy I hope I dont smoke it . Please change the music thank you

[@ryeosborne]

I have this exact receiver that I just picked up and it has a faulty protection relay I believe. When I got it home and cleaned it and plugged it in (without plugging in any speakers of course), and the relay keeps clicking off and on. So mine needs very similar work, and I have no abilities to do it myself. Could I inquire about your services?

[@MrDoneboy]

Hey Aiden. Another good source for your repairs would be Chris, from Vintage Audio Addict, if you ever get stuck on an issue. Cheers!

[@Thetimeisnow78]

I just purchased one from goodwill… I sit down to get more info on this receiver and the first thing I heard is. “ this is the 3rd one on my bench this year. These things all have bad transistors and go bad” I was like OH NO😢 what did I just get into? I guess I’ll find out soon as it arrives.

[@paulbathe1130]

What is the name of the company to get lamps from. You said it so fast I can not get it...Your video is easy to follow...Keep posting!!!

[@RobertHewitt-fy4eg]

Hi i've got a pioneer sx434 speakers work fine on FM and AM but not through phono for turntable

[@afzaalkhan.m]

Thank you for your excellent videos Mak Pakistan

[@asexualnonbinaryoterkinfem6236]

Sir i have a pioneer sx737 from my dad he lost his life I absolutly love the sound of this system. But I hear cracling sound I try restore it by neiborhood but I still here static noise. I Need a professional to clean and restor that thing. I Open it today and its a real nasty dusty mess in there. Can ya help man?

[@davidtalon5553]

You rule dude i have one myself, it still works! but when i turn it on! it makes a buzz sound for 1 second and after it plays like a bell , can you give me some info thank you so much David

[@robertlundstrom8061]

You said that you got replacement lamps from where???? When you mention such things it would be nice if the name and/or website came up on the screen.

[@thomasmurray8399]

How much did the repairs cost ? Thanks

[@paulpower2680]

I just dug mine out of the garage. Wanted to use it on the patio this summer. Turned it on. lit up for a second then shut down. I need to find someone around here who knows his or her stuff like you do!

[@davewilliams5932]

Hi, i have the same receiver with same relay problem. How many transistors did you take out and what are their numbers?.

[@LilB1981]

This is the exact same thing mine is doing, I would love to have mine back in action 😢

[@benfregeau2290]

Hello, love your videos! I have an old Pioneer SX-828 that was working fine for about 2 years after I bought it. Now when I turn it on, I get normal sound out of it for 10 minutes or so, then it clicks off and produces no sound at all. If I leave it sitting there turned out, it produces a single "click" every few minutes. Any ideas?

[@insolentstickleback3266]

Excellent video, very much enjoyed! 👍🏻

[@MrPruske]

So what would cause the MS4U to buzz when power is applied?

[@kennethiman2691]

Might be helpful to know how much actual time you have in a repair. I think a lot of customers don't understand how much time you can have tied up in a repair.

[@oscarochoa843]

Where can I contact you I just picked up one it was given to me for free and Has no power

[@Tonytheman214]

Look for when the prote circuit kicks and focus on that area like I did

[@davewilliams5932]

where can I get them, if you don’t mind me asking?.

[@geminijinxies7258]

Nice video! It's good you replaced the transistors because they'll probably stop working sooner or later anyway. I have a question. Do capacitors age when they're not in use? As in no electricity running trough them.

[@corsav74]

Yes they do, although my guess is using them speeds up the aging process by some degree. The electrolytic fluid dries over time, regardless of usage.

[@Poppinwheeeeellllllieeeeez]

@@corsav74 actually using them is better than sitting, but the elctrolyte dries out and they pass dc current. Seen as a dc transient on the o scope. They lose capacitance and increase in resistance. Sometimes caps can be reformed by passing voltage through them. The current breaks down the oxide layer that is passing the dc current. Always best practice to replace.

[@honestjohn6062]

Static volume noble ,what the fixs

[@crimsonghost6454]

I love your videos. Just keep doing what you do. On a side note , I will be doing timing chains on my old Jag soon. I wish you had a video on that...

[@berylhemmings7003]

In ur intro u sound like good radio/tv the right flow try try it

[@icemiike713]

Mine power on but no sound, radio, nothing 😢

[@davewallace8219]

I'm getting back into vintage audio...I'm trying to learn the name...purpose of componets...as well as basic sections...of the reciever...as well as basic diagnosis...thank you for your videos...

[@davewallace8219]

thank you

[@magnoliatom1300]

I’m looking at getting a vintage receiver like this. I’m looking at the pioneer sx 737 or a Technics sa6000x. Are they comparable or is one better? Thanks

[@tylerjezowski5633]

Did you try power washing it

[@robertdavis5714]

Nice production. Any Pioneer with the Blue Glow I stay away from. solid state electronics was still at it's early development. I got a job for ya, will make a good video, no problem mailing to you. Kenwood 9000G with blown power transistors.

[@reneneron2971]

Curious…what do you do with all this vintage equipment once you repair it?

[@janicehopkins4432]

@David Clark cleanliness is next to godliness :)

[@GF-ok5yn]

Thanks for this Video, I seem to have the exact same issues on my SX737, and the checks also lead me to the faulty transistor, I have just ordered some KSC1845,s. Keep up these great videos.

[@think2023]

4000x? Great way to up the flat rate paycheque. I was using coffee...not nearly as effective! Lol

[@1MotionPat]

I have this same receiver, and really enjoying it! But do you think it's feasible to hook the meters lights to the phono? It's only on with the others inputs.

[@jetsonIFY]

Great work! I will be doing thee same thing shortly with an old Roland 201 echo. Caps I would just order appropriate values from Mouser. However how do you find replacements for transistors. Is there some sort of spread sheet of modern for old ?

[@afoxatemyinternet4215]

Hi loving the cannel & the concise explanations, any chance of posting a link for the compatible transistors. I did grab a screenshot in one of your other vids but not all are listed.

[@dj33036]

I'm in Mexico, I wish I could find someone here with your patience and expertise to work on a couple amplifiers I have.

[@FortyTwoAnswerToEverything]

Is that a Dell 9575 / Precision 5530 2-in-1? We might be bros

[@markandrew7867]

Great video. Protect circuits are kind of my nemesis. Thanks for guiding me through it!

[@jamespeter9720]

I am mostly a Marantz guy and have never owned a Pioneer. Your videos on these Pioneer units have certainly piqued my interest. I am looking forward to owning one of these soon.Thanks again for some really awesome videos. Cheers from Kuala Lumpur,Malaysia.😁👍

[@Frank_nwobhm]

Best vintage electronics repair channel on YT. Informative and fun even for someone like me who'd be all thumbs if I tried to do this stuff.

[@markpro8039]

enjoy your videos quick question does the output transistors on vintage receiver sound change with todays equivalent transistors

[@stacenrob1977]

nice work

[@DerekHundik]

what happens with Pioneer SX-750 ?

[@wayneg296]

👍👍😎✌️🤟

[@JamesE707]

The permutations of the causes of a fault can be massive.

[@jorgeandrade20]

I always enjoy all your videos. Question: at 9:15 when you say you tested Q7, Q6, Q5, could you clarify? How do you test them? Do you remove them from the circuit? What meter do you use? Thanks!!

[@AHFixIt]

I removed them from the board and tested them with a Peak Atlas DCA55.

[@spacemissing]

I don't see a suppressor diode across that relay. Maybe that's one reason so many Pioneer receivers have such problems.

[@envisionelectronics]

I had the pleasure of repairing a Pioneer M-22 that has protection diodes across the relay and the transistors still died. They measured okay - just lightly leaky. They were a pair of 2SA945.

[@PioneerGuy581]

these are clean units. just did one.

[@alanlee2516]

Thoroughly enjoy your videos. Can you share the total amount of time it took you to repair this receiver?

[@AHFixIt]

Days. These videos make it look much faster than it actually is. I am not fast in reality.

[@R.Akerman-oz1tf]

Greetings sir, re:drivers 2sc458lg, 2sc497 & 2sa497. I can't find a listing for cross ref. Any ideas? Thanks so much.@@AHFixIt

[@CaptainSisko1972]

Love your channel!

[@nielskjr5432]

Great work! 👍

[@dalemcspadden943]

This guys cute 😍

[@oscarochoa843]

Do you have Instagram by any chance so I could contact you