Fantastic work. I can only imagine how many good pieces of equipment got thrown out due to "cold" solder joints. You have a great mentor.

Not an electronics repair person I'm an HVAC/R tech but thanks for this video. Very helpful. I followed the steps outlined here ad found the same problem. I did not jump the 13v. I just touched the solder joint with my meter lead and the relay clicked right in. Now to re-solder!

I remember buying the same receiver at a garage sale , The person told me it did not work . I took the chance and bought it .($25.00) It did the exact same thing you just encountered . I have been listening to it ever since !

I just picked up one last weekend in PA, the guy bought it new when he was 16, he has never had it open, never serviced, but he took very good care of it. I am going to do some cleaning and inspect for any obvious signs of failure but otherwise I am not touching it. it looks and sounds incredible. I will run it a while, no dc on th outputs.

Excellent description of what happened and good troubleshooting. I wish the problem with my pioneer m-90 was this simple

I own a beautifully clean SX-780 , including the original box, that I bought from its original owner. Unfortunately it seems to have one or more of these same problems. I hope to repair it some day, but for now I'm too busy servicing other people's equipment to work on mine.

Really appreciate your videos, thank you. I have zero knowledge of how this stuff works or how to fix them but these videos provide a great introduction for me. Thank you!

I just got one of these out of a dumpster and this video plus a drop of solder had it firing right up! Many thanks ✌🏼

Thank you! Just fixed mine which was doing the same thing. You saved me some $ my friend as I was about to take it into the shop. I just touched the 3 points with my soldering iron and...relay began working again.

Thanks man, your video was a huge help. Picked up one recently with the same issues. I switched out a bad Darlington pack qnd it lit up but no sound and no relay click. Re-soldered the resistors and Boom -- IT'S ALIVE! This receiver is a Beast and sounds awesome..

Excellent Video! Something similar happened to my Nikko NR 1015 and my friend that fixed it did the same thing with lots of solder. Nothing like hearing that protection click come on again. Nice 👍

Good one. I was all set for you to explain, how the power pacs, were hard to replace, because there were too many faulty knock offs available.

Very to the point video. For the future you should check the whole receiver for cold joints.

this is valuable for the layman...it may help in dealing with used gear...thank you for your effort...

I can't thank you enough for sharing this tip which helped me get my receiver back up and running "Cold Freaking Solder Joint" thanks again my friend!!!

Excellent diagnosis and fault rectification

Nice easy fix in the end. Excellent video as always

Still have and use my 780 from high-school, bought late '70's

Lol like clockwork!!! This is becoming a big part of my Friday lunch routine😅 thank you!!!

Good video! A lot of 70's era Pioneers have bad solder joints at the 13v supply transistors. Even if you're just giving one a quick tune up, they're worth reflowing. Cold solder joints don't typically form because part of the solder melts, though. It's because there are different types of metals involved that expand and shrink differently throughout the operating temperature range. The push and pull over several thermal cycles eventually creates a small gap where the material is packed together, then drifts apart as it cools

Oh man I used to own one and gave it away when one of the channels failed. Wish I had it back.

Bought mine in 79. 5 years later. No click, power on. Took it to a local shop. It was just the switch. 20 bucks. Still good today!!

God Blessed youI I am very happy today -4/22/2023 It is the easiest fixed I learned.

I love the vids. Trying to learn this stuff and “immersion” does work.

there are also 2 pots that set the DC offset for Left and Right. Try TP 6 to gnd AND TP 9 to gnd with those blue pots

@ScottFrye000111222

Жыл бұрын

YES!...SAme transistor problem. Resoldered and Whoomp, there it is

It would be interesting to know the relay threshold. Thanks for the great vids.

In my case it was a cold joint on collector of one of the power supply transistors that provides 13V for relay coil. Exactly the same one you resoldered. Looks like it's a common failure and main culprit. It's nice to find out your fix was cheaper than expected - at first I thought it's the power packs that failed

Great video. I fixed my Pioneer SX-1080! I was getting intermittent click no click of the relay. I found 3 cold solder joints. Hit the 3 joints with solder and problem is fixed. If you would consider doing a Pioneer SX-1280 receiver recap repair job for me let me know.

Have done the same thing and guess what? 😂 It has worked out 😅 Really appreciate your tips. God bless you brother

Good thing the Darlingtons are still working.

Thanks for the great channel 👍🏻

You might want to give some thought to a bench power supply. Keep up the good work!

AH!?...I mean MAN!!..Mr.AH. your just a Genius!!! I shall get to work

Aidan- I am glad you got an easy one this time. You have had plenty of "posers" already.

Muchas gracias por este video 🙂👌 thanks for share

I had an SX with digital station display with an analog scale and dual radio tuning meters and I think it had analog power meters ..I cannot remember the model number .......Have you had any experience with the new Luxman amps tube or solid state ? That would be one of the few of the new stuff I would buy theses days ..

Noob question: Can anyone please suggest which current combined receiver/amplifier would provide similar quality output as an SX-780? Thanks.

First, always use a dim-bulb for testing. Second always check the supply voltages. This issue is common on the SX-780, it's a design flaw and will happen again. The real fix is to replace that transistor with a higher wattage one AND replace the heatsink with a larger one. As a matter of fact all 3 voltage regulators should be replaced with higher wattage types and larger heatsinks be installed.

@davewallace8219

2 жыл бұрын

good stuff thank you

The next time you'll see this unit is when the Darlington Power Pack tanks. It's only a matter of time. Those things are garbage. Great vid!

After you re-soldered the cold joint, we’re you able to get a 13.5 V reading from either the joint or on pin 1 of the PA3004? I’m experiencing this exact same problem but not able to find ~13 or 14 volts on the Q25 circuit.

I recently jumped into the vintage pool with the purchase of an SX-780 and your videos were definitely a motivation. One thing I noticed is that both the loudness and power switches are angled slightly inwards as opposed to sticking straight out. I've never seen anything like this before so I'm assuming the prior owner did this for some reason, but if anyone knows if this is actually supposed to be like this from the factory, I would appreciate your insight. I have resisted bending them back in just in case they are in fact supposed to be like this.

@Evan-tj1te

8 ай бұрын

Since no one answered...no, they are supposed to be straight out in front, not angled at all. I would say they probably got whacked at some point and bent. You can bend them easily enough by using light pressure and bend it slowly.

@SeanSisco

8 ай бұрын

@@Evan-tj1te Really appreciate your response, thank you so much!

I am no tech but learning, I do Marine and Automotive wiring and electrical components, My question is if you are there and you have a cold joint problem and know that the Transistor has gotten really hot wouldnt you just go ahead and replace the transistor as a preventable measure ? I would of replaced it they are cheap enough .

so this receiver taks the darlington power pack stk-0050 do u know where a person can get these

Good afternoon sir I loved your video. I think I have the exact same problem. I do not hear the Click but everything lights up as you should. I'm hoping you can help me out.. Do you have any info on anybody that does restoration on my SX780 Pioneer... I live in Orlando Florida anybody you can recommend I will appreciate it thank you sir have a blessed day.. It's trying to reach out to you I saw your video... I'm a veteran this is what gives me a pleasure I'm just listening to my old records on my receidear thank you again

Your bench height would be perfect for me. I had to add wood under my bench legs to raise it up. It’s nice to have a sit down & stand up bench.

Do you have any experience on repairing the wood portions on the SX-780? I just purchased one from Reverb and it has issues with the side areas. Thxs

I've been following all your videos but I got a quick question for you please period hoping you can help me out before I do a bad investment I have a Pioneer S780 and took it into a certified Tech and he tells me the preamp circuit board went bad and to repair it's gonna cost me $400 it's that is that a fair price???

good work, maybe replace Q25 too. How did it sound? Thanks for your work, r

Love your videos. Found my 'cold' solder joint and not I'm back to annoying my neighbors. Life is good! I have a question someone might be able to answer. I have tons of tracks on my usb stick that I would love to play on my pioneer. What's the best way? Ideas? Thanks....

@chillipaha8130

5 ай бұрын

I have an sx 1250... I use a DAC w/bluetooth called Slash6, it's amazing! I connect my TV using audio fiber out to the slash6. RCA jacks on the slash6 to my sx 1250 Aux channel. My TV has a USB port for movies or music. The Bluetooth feature can also connect to your phone or computer for the USB. Hope this helps... Amazon has the Slash6 for $162.00.

Hello sir,I am admirer of vintage high end amplifier, receiver.Sir is it possible to make a pcb of this amplifier.Sir I desperately looking for a pcb of this amplifier,not particularly this one,Technics ,Marantz will also do.Plz help sir

Did you end up circling back to the excessive offset on one channel?

Thats the only repair I know how to do for the most part on circuit boards & have been fortunate enough to fix quite a few things / dozens over the years I use a non conductive probe/ a chopstick & push on any questionable solder joint also a magnifying glass I first figured this out when I had a TV tech from the shop I worked at try to fix an erratic problem on my $1000 Sony back in the early 90s & couldn't I fixed it the first try & still use it in the spare room now 30 yrs later most recently I fixed an older garbage picked Yamaha reciever & have been using it for over 6 mos.

thank you....

Hey! Curious, I have a Pioneer SX680 and in thinking about buying and connecting it to a smart plug. This way, the unit will automatically be turned off and save the bulb life. Is this a bad idea?

@AHFixIt

2 жыл бұрын

I don't see anything wrong with that

Hi i own a 4270. I also have FOUR acoustic research speakers, all 8 ohm. One pair is AR2AX, the other, AR-12. im going to put them in quad mode, 4x25 watts. Question for hooking it up : one pair of spkrs connected to the FRONT MAIN spkr terminals and the second pair connected the REAR REMOTE terminals ? Or, should it all connect to one side or another, that's to say, all on MAIN, front and rear, or all on REMOTE, front and rear. Much thanks. !

@AHFixIt

2 жыл бұрын

Doesn't really matter. That just determines which speaker switch in the front controls them. I'd go MAIN and MAIN, though!

@skyblinked

2 жыл бұрын

@@AHFixIt hi buddy, ill try it out, let you know how it sounds. No videos on YT with 4x25w on the 4270. Thanks for your speedy reply.

What kind of speakers are those on the bench? Lol. Love your repair vids by the way.

@sallyanne8815

2 жыл бұрын

They look like advents

I have the same receiver but I don’t think mine is making as much power as it should be. I know it could be one of a million things but does anyone know what that could possibly be? Maybe the power pack is going bad? Any suggestions would be greatly appreciated.

@erikdenhouter

2 жыл бұрын

Most likely one of the coupling electrolytics at the input of the pre-amp or power amp. But... that would almost always show in a difference of level between left and right channel, because they will not easily fail on both channels at the same time. Don't think it has anything to do with the power supply.

@K-Effect

2 жыл бұрын

@@erikdenhouter Thank you for your help, that will give me a great place to start

I just spent half a week tracing down cold solder joints in my Miata's OEM cassette deck. Dismantled the whole complicated mech looking for why it wouldn't engage the tape... and it was a cold joint in the connector all along. Keep an eye out for those bastards. They sneak up on you.

2fm radio 2sa726 q7 q8 used as buffer amp needs to be replaced If the volume is turned down, there will be noise.

Excellent job, Sir. What's your address so I can send you mine? 🙂

Left drying in the west phoenix sun.

if I may ask , I bought a used SX780 and I cant get a stereo signal on FM. hoping its something simple . I get stereo on all other outputs(headphones,CD, Tape)any thoughts

I have a SX-780 ... 👍

Mine lasted 5 years. Had a house fire and got insurance money to buy an Onkyo

Mysterious thing happened with my notebook, notebook on, went to my kitchen to get a cup of tea..after some minutes returned and saw a strange message....that there wasn't a boot device.....restarted the notebook but again the same message. Took the ssd out to check it via an adapter connected to another notebook ....but before that procedure pluged it in the original notebook and? Problem was solved...... Later i remembered my brother had the same with his micro-pc 14 or 16 years ago.

Ahh yes... Pioneer and their common Cold solder issues :p If i am correct, I have repaired in the region of 30-40 pioneer amplifiers and receivers..... and i'd say, 98% of them have been cold solder joints

@chillipaha8130

5 ай бұрын

In your findings, what would cause my sx1250 on a cold start to take up to one full minute for the second relay to click? On a hot start it only takes 4 seconds. Thanks!

@marianavelino6081

2 ай бұрын

Same with my Father's Pioneer SX-650, Relay s not working. FM is in stereo mode but no output at all. I remember, when you switch-on, after second you hear 'CLICK". This time, I can't hear the sound click

Ur cute

I pray every time I turn on my 780 that I get the click. :-) Hopefully my power packs never go bad. I have seen how you can replace them with a small board of discrete components.

@marka1986

2 жыл бұрын

Xraytonyb has a nice video on discrete replacement for the stk 0050.

@larryhermes1676

2 жыл бұрын

I did the mini board that tony did. Not a technician but tried to learn what I could. Fun little project and it actually worked. I want to borrow my son’s scope to see what the signal looks like and power output. Just from my ear sounds really good.