Pioneer SX-880 with a short circuit...

This pioneer was the last in the 800 series, built in the late 70's at 60 watts was indeed a powerful receiver... this unit came on the bench with a short circuit...watch my video and see how I repaired it back to life....
Thank you for your support! and PLS subscribe to my channel.
#shortcircuit, #pioneersxseries, #pioneersx880,

[@4211Rob]

Excellent job on a beautiful amp! Thank you for showing your thoughtful procedure.

[@kenrolle2338]

Nice to see discreet transistors for the outputs instead of those dam darlington packs.

[@fernarias]

There are upgraded solutions for darlington packs and many other issues for pioneer.

[@MsHarry67]

Joe, your videos are always instructional and educational. Thanks.

[@VintageAudioFever]

Glad you like them!

[@collinwood60]

Another gem Joe. Gold standard for audio equipment repair channels as far as I'm concerned. Camera work is excellent. Zooming in on the exact test points for various components is so appreciated. Most other repair videos put you in the ballpark, but you can never quite see what they are doing. You are so good at explaining everything as you go. Very helpful for someone like me that's trying to learn this stuff as I own quite a bit of vintage HiFi equipment. Look forward to the next tutorial! I wish you were located in my area.

[@yambo59]

I had a friend bought one of these brand new in the late 70's and it was rated at 60wpch @.05% THD so you have it dialed right in id say, doesnt get much better than that.

[@VintageAudioFever]

Appreciate the info!

[@apolinarmartinez5723]

Pioneer its my favorite amp brand, beautiful equipment, nice job, thanks to share with us you knowledge.

[@richardmacphee2367]

I picked mine up 20 years ago at a yard sale for 20 bucks, I recapped it this winter, I found a service manual from an old technician that had a service bulletin for that hot transistor problem, if you send me an email address or post office box I’ll send you a copy of two ways they fix this problem, it involves relocating it, pretty easy to do, keep up them videos 👍🏼

[@afzaalkhan.m]

Excellent diagnosis Thank you

[@allenfleckney5969]

You get to work on some beautiful units , this one especially. Hope you’re well, keep it up.

[@Fanan67]

Joe that Pony tshirt brings me memories from the 80's....

[@timcorner2821]

Great work again Joe....I'm awarding you the Pioneer SX-Series Award for this month...lol

[@steveoszman8746]

Thank you great vid, love them old pioneers.

[@Atelierul29]

When you don't have the exact replacement part, you should swap the other transistor too, even if it's good. These guys work better with their respective complementary transistors.(MJE15030 and MJE15031 in your case)

[@craigm.9070]

Thank you for your time, you straightened out a very god receiver for another run at life.

[@louoldschool7047]

nice work, I have a lot of receivers but nothing like that

[@ahmadalawadhi538]

Really I love to see your videos olways I learn something. So professional work god bless you

[@VintageAudioFever]

thank you so much!!

[@videocast3655]

excellent troubleshooting Joe. the experts on Audio Karma recommend beefing up the heat sinks on the regulator transistors on the 780 for the same reason you have on the one thats extra hot. a very common problem it seems.

[@mdzacharias]

I've seen this on a couple of your videos. You can and should also check emitter to collector on those outputs. The diode check will just show zero if shorted or open if good, probably give a continuous tone on a short, though I'm not sure about that on your meter. I've seen E-B and B-C junctions appear to test fine and still be shorted E-C.

[@dirtydon8661]

Listen to this tech!

[@johnnytacokleinschmidt515]

I've been there and done that. Check all three ways.

[@davewallace8219]

You describe your procedures soooo well! Thank you!

[@kennethiman2691]

I usually add additional self adhesive heat sinks available on Amazon.

[@a587g]

Nice job on this! I've got one as well and it's a nice unit with lots of power. Love the black meters on this series, though I do feel the x2x-x5x sound a bit warmer. Still, no complaints!

[@sand0077]

Maybe a same value but higher wattage resistor would help with the heating issue?

[@voenigs612]

I'm always amazed at how long you leave a device switched on despite a short circuit. OK, currents and voltages are lower when a light bulb is connected in between, but a short circuit is a short circuit.

[@davewallace8219]

Thank you!

[@gordthor5351]

I think it's not worth the sacrifice to avoid a bit more heat at the loss of higher bias current (less crossover distortion). Not to mention it will take longer for the amp to warm up to optimal operating temperature where everything is stable and where it is tuned at. Hence, the reason to wait until the amp is heat soaked to set the bias. If the range is 20-40 mv, I am setting it at 40mv for the best sound quality. Who likes crossover distortion?

[@alexzildjian]

Muchas GRACIAS 👌☺️

[@JoseVargas-uk3lt]

Beautiful work, but then again, I’m biased because I have the same receiver.

[@VintageAudioFever]

PS...I'm shipping you your box this week

[@JoseVargas-uk3lt]

@@VintageAudioFever thanks Joe.

[@JoseVargas-uk3lt]

Joe was that enough $$ to cover the cost ??

[@2wrdr]

I may have missed it, but did you check the same transistor in the other channel as a reference with your temp checker? Also, maybe check after bias adjustment to see if still hot? A screenshot of this transistor as shown in schematic would help those of us not familiar, just a suggestion for future vids. Cheers!

[@bobdoritique7347]

Merci for this video. Very well explain!

[@VintageAudioFever]

Glad you enjoyed it!

[@MichaelSJouper]

Hi! Tomorrow i have a plan to do the adjustment and also make a note too you 👍

[@VintageAudioFever]

Please do!

[@MichaelSJouper]

Hi The bias before was 28,9mV and 28mV, DC out 1.5mV and 1,9mV Power Supply was little high 38V and adjusted down to 35V as you showed in your video. Thanks again for all nice video and i learn a lot from it

[@g.fortin3228]

Nice job Joe ! I'd like to have seen the bias tested after adjusting t eliminate the dc. Just wondering how much it affected. great receiver there I love that series.

[@VintageAudioFever]

Great point!...I will do that next audio...thks

[@Hagis2k]

Just found your channel great repair those old amps from Pioneer are beasts and it has the same output transistors as my old HK 870, and I noticed you have pretty much the same magnifying glass on the arm as me :) can it also switch color temperatures? I had the little controller on the cord, but i replaced it with a 2ch rf dimmer unit, and I also 3d printed a new triangular bracket that is closest to the lamp part now I can hook up a small camera to the light. And I think you might have the same variac as me too it looks pretty much identical.

[@VintageAudioFever]

hi, I read you comment...thank you! I just subscrib to your channel, maybe post a pic of your shop someday... have a great wkend...

[@minephone7241]

I'd really like if you explain what and why you're doing while you're doing it. That would educate us a lot. Now I hardly understand what is going on.

[@minephone7241]

So for example you could be explaining what is bias and why and how you're regulating it.

[@BStrapper]

hi Joe, I like your vids it would be helpful to show on the schematic what you test and why, And what is the logic behind it... so that way all the green-horns like me could understand what you do and why... without explaining on the schematic what you do only the "experts" understand your explanations... And those don't need to listen to videos about how to fix amps...

[@johnc.4625]

I have a pioneer elite that I’m looking at. The relay clicks about 5 times but won’t click in. What would you check first? Thanks

[@MichaelSJouper]

Nice video. i must adjust my Bias on my Marantz 2238B after that i replaced all old capacitors. i see that its necessary after all years

[@VintageAudioFever]

it's not always necessary to reajust the bias after you have replace a few caps but I always love checking that on my part...but here's a idea, why don't you let us know what you had for bias before and after...

[@Gary-qq7og]

Great job, i would like to see someone work on MAC1900 receiver on you tube. My Mac's lef channel went up a little puff of smoke it had been running a little hot before it quit on me .

[@VintageAudioFever]

well maybe someday I will have a mac on my bench....

[@gregnewberry4813]

If you don't mind me asking... What source did you use to cross the old transistor to a Motorola MJ? Thanks

[@jameshopkins7333]

Hello Joe, Working on a sx-1500td given to me. Missing the power transistors and six others plus two were replaced with 1845's. I think they were in wrong. the emitter resistors were missing also. Blowing the fuses when I replaced everything. Did you say you powered the 880 up to test the emitters ? On the dim bulb tester? Thanks for your time brother.

[@VintageAudioFever]

Hi James, I will always power on the first time on the bench through DB, if I detect a short then I will shut off the unit and I would test outputs and move inward, if you need voltage to do further testing, use a VARIAC and DB both at low voltage....in your case, your blowing fuse, it takes major short to blow a fuse, like I said, concentrate on your outputs and move inwards, do you have voltage on your emitters/resistors?

[@jameshopkins7333]

Thank you sir for your good advice, I use the DB. Will use my variac for further testing and get back with you on my progress.@@VintageAudioFever

[@Expedition18]

Where can i get schematics of my sx880? Also love the turntable killer idea.

[@VintageAudioFever]

Hi... google search "pioneer sx-880 service manual" and download elektrotanya service manual it's 45 pages but all you need is on there...

[@Expedition18]

@@VintageAudioFever awesome thanks

[@martyndavison5259]

how can the heatsink be hotter than the source of the heat , the transister ?

[@VintageAudioFever]

I actually did experimental and changed that transistor with a new one and same thing...it's not the transistor, I know that for a fact....but here is my thing, I could of change that whole circuit board with new parts, I would still have Q26 as a hot spot....

[@BhagirathChoudhari-s6p]

Circuit diagram for reaper

[@lnglng6961]

❤❤❤🎉

[@ladronsiman1471]

You should have changed the transistor itself .. and caps around it

[@VintageAudioFever]

I did a experimental with switching that transistor with same results(HOT) ....it's not the transistor...

[@leszekalbin4097]

👍🏻👏🏻👏🏻👏🏻🙂🙂🙂

[@moodyga40]

easy amp to fix this one

[@MarkHiFi_Guy]

We're are you located?

[@n.lyndley.9889]

Where

[@VintageAudioFever]

I am in Moncton

[@VintageAudioFever]

Moncton

[@MarkHiFi_Guy]

Great videos,,I admire your passion and skill,,,very hard to find great techs like you ,,,I wish I could find one like yourself here in Hamilton Ontario

[@tomaszbekiesz3732]

You know when heat sink has higher temp. than the transistor it's cooling there must be something really wrong with the lows of Physiks in this transistors sorounding space 🙂

[@tomaszbekiesz3732]

good video though

[@VintageAudioFever]

Hi as I said on my video, I did check all of surrounding circuitry but everything check out ok....

[@W1ZY]

Impossible for the heat sink to be at a _higher temperature than the transistor._ This violates the Second Law of Thermodynamics. Should have replaced the other driver transistor paired with the blown one.

[@VintageAudioFever]

I love comments such as this one... very productive, and everyone learns ... Thank you, 👍 👍 👍

[@AstrosElectronicsLab]

The heck is "RMP"? Don't you mean RMS?

[@VintageAudioFever]

Hi....you have a curiousity, I'm not sure if I said "RMP". Where abouts on the video? I did go back where I thought it might be but I didn't see anywhere where I would of said RMP....but RMS would of been something I would say along the line....

[@AstrosElectronicsLab]

@VintageAudioFever towards the end during the power test you had a title card saying rmp