Pioneer SX 9000 repair

brianhiatt

New Member
hello,

I thought I would post a few notes and where I am with a recap and some troubleshooting of a my daughters Pioneer sx-9000. Since I find only a little data on this unit on line I thought I would share what I did and the outcome.
 
They are full of known trouble maker transistors.
Head amp, pre amp, reverb. I've found they should all go.
The reverb ones will cause signal noise even with the reverb turned off.
I have another one here now that I need to re-transistor as soon as I get a chance.
 
For this project I did a few things:
1. clean the pots with deoxit D5 and deoxit fader lube
2. replace all electrolytics with a combination of my favorites (in order, please don't ask why, I just like them, who knows what are best...not me)
  • Elna Silmac II
  • Nicihcon
  • Panasonic
3. cleaned the boards with super wash from MG chemicals and removed any flux with MG chemicals flux remover
4. troubleshooting of an issue with no power to the left channel
5. set the center point voltage by following this artical here: http://audiokarma.org/forums/index....-center-point-voltage-bias-adjustment.650259/
 
They are full of known trouble maker transistors.
Head amp, pre amp, reverb. I've found they should all go.
The reverb ones will cause signal noise even with the reverb turned off.
I have another one here now that I need to re-transistor as soon as I get a chance.


Thanks blhagstrom, I say this on a couple forums. I think I am lucky as the transistors all seem ok but I tell you what the reverb sounds horrible so I think I may swap those out and if it does not make it better I might remove from the signal path.

Thanks again
 
2016IMG_3035-XL.jpg

bottom boards prior to changes

2016IMG_3029-XL.jpg

Top from the back prior to changes
 
Here is an example of one of the boards being recap'd

2016IMG_3045-XL.jpg

Old caps, all are Nippon Chemi-con

2016IMG_3049-XL.jpg

caps out, check out that shmoo, yikes, they are WAY out of range, some are much more than 50% out, I think one was 100% or close


2016IMG_3048-XL.jpg


New caps in!
 
2016IMG_3134-XL.jpg


Here are the new filter caps and, yeah, some Vishay bypass where I had not choice, gotta use what you can sometimes.
 
Once all caps were in I used my variac to test it out, now magic smoke and all seemed ok.

Next hooked up some speakers to test it out and found one channel was not working at all....

So, this took me a day or so to figure out, in hindsight it was really really simple. On the main amp board I could not get it out all the way and so, I missed a big issue, I had a bad resistor and once I took the board out to look at it closer I found the issue.

2016IMG_3158-XL.jpg


You can see the bad stuff I missed and the broken resistor, what a mess. I missed this, so now it's clean, all four resistors are replace with new ones and all is working again!

One thing to note, two of these resistors are 3.3 K and the manual and documentation all show a 4.7 K resistor in that slot. I decided to keep them at 3.3 k as that is what has been in this for a long time but not sure if that was the right thing to do.
 
Cleaning

I cleaned the pots with Deoxit and worked them several times over a few days and they all work really well now.

Here are a couple pics of them while the boards were out.

2016IMG_3057-XL.jpg


2016IMG_3051-XL.jpg


These three are really buried in there...
 
So this is really it, the thing sounds great, not the best in the work but so much better than most modern equipment.

Hope this somehow helps one of you, I have more pics if you need them.

2016IMG_3160-XL.jpg


Here is the completed bottom of the unit
2016IMG_3162-XL.jpg


Here is the completed top of the unit


Cheers
 
Oh, one mode I made, I replaced one of the speaker outs so I can use it with banana plugs


2016IMG_3136-XL.jpg


This is the odd terminal block Pioneer used in this model.

Replaced it with a piece of sheet metal with two Pomona banana plug connectors.

2016IMG_3161-XL.jpg


The binding posts are Pomona 6883, dual binding posts, seem to fit ok, a bit tight but I did not have to cut the case for them.
 
Nice work.

After doing a few, I think there should be a special club for those of us that restore those.

It's a lot of work.

But worth it.

Welcome to the club
 
Wow, nice job ! I have not done all caps but only the large ones (Panasonic). My SX-6000 sounds great already. Here's info on what I did changing the lamps: http://audiokarma.org/forums/index.php?threads/sx-6000-restaurantion.738190/

Ordered the binding posts you suggested, thanks for sharing.

I would like to change the colour of the "wood" case but am afraid of start sanding it: Its this vinyl or real wood veneer? I have the impression is vinyl but am not 100% positive. I'd like to sand and give a lighter colour so it matches the L75 turntable .
 
Wow, nice job ! I have not done all caps but only the large ones (Panasonic). My SX-6000 sounds great already. Here's info on what I did changing the lamps: http://audiokarma.org/forums/index.php?threads/sx-6000-restaurantion.738190/

Ordered the binding posts you suggested, thanks for sharing.

I would like to change the colour of the "wood" case but am afraid of start sanding it: Its this vinyl or real wood veneer? I have the impression is vinyl but am not 100% positive. I'd like to sand and give a lighter colour so it matches the L75 turntable .

Thanks, Thanks for the link to the lamps, I really want to look at that too perfect!

My case is a veneer on plywood. I just cleaned it up have a spot thats really bad on top but like you, I am not sure it's worth fixing with new veneer for me:). I have no idea if you could sand deep enough without ripping the veneer, I do a lot of woodworking and don't think I would try that but I am not a veneer expert by any means.
 
Why does no one attache a front view of this receiver. This is true of threads other than this oneI have never seen one and am dying to see what this critter looks like. Please. :bowdown:
 
Yea - I did repair one of those!
I got it and some tips from "Blhagstrom" a few years back.
Replaced the amp drivers and outputs, recapped and it was working.
Sold it to a buddy and he loves it. Doesn't want to try anything else.
I get a handshake too.
 
Why does no one attache a front view of this receiver. This is true of threads other than this oneI have never seen one and am dying to see what this critter looks like. Please. :bowdown:
Here's what one looks like not powered up. Very nice sounding receiver. Disregard the beer cans and butts.:biggrin:SX-9000.jpg
 
Nice! Thanks for the pics. It looks similar to the SX-990 that I used to have. Mine had a spectacular tuner.
 
Yea - I did repair one of those!
I got it and some tips from "Blhagstrom" a few years back.
Replaced the amp drivers and outputs, recapped and it was working.
Sold it to a buddy and he loves it. Doesn't want to try anything else.
I get a handshake too.

You're not a "real" Pioneer tech until you rebuild one of them.
Now, about this QX-949. If you want gold plating on them Pioneer wings, you got to do one of these too.
 
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