Hello All - Busted SX-950

Sorry, I didn't see this

"a) Yes, jumpers in, and also hooked up a source directly to the pre-in to eliminate this circuit as a problem"

I'm watching because eventually I will have to do this myself.
 
Ran the whole order through Mouser. Wow, $15. It's the $20 shipping that sucks.

Will run by a local electronic supply store in the area tomorrow. Possibly they have everything I'll need for this. Regardless, it sounds like the transistors and trimmers are the essentials?

Wife is going away for a few nights next week - a perfect time to do some soldering.
 
Where do you live? $20.00 Shipping? OUCH!
Remove the big outputs and heatsink(s). dont put them back until you have the amp board repaired.
Test them using EW's "Bipolar Junction Transistor Testing Basics" Thread

http://www.audiokarma.org/forums/showthread.php?t=43186

You will need Thermo paste and Pro wick desoldering braid, or better, a solder sucker. Well, what kind of equipment/tooling do you have?

If you have some old useless equipment PCB's laying around, start practicing on desoldering components on a junk board.
 
TSD71 knows the 950'2 well, but if I remember, you can remove the outputs and heatsinks. Then the whole amp board with the output sockets can be slid through the chassis cutout and end up on the bottom side of the set. Excellent access!
 
Well Zeb and Beat, I have some bad news.

The unit is working fine, and I also now know why the main fuse blew.

I was trying to take the main amp board out tonight, or at least figure out how to most effectively disconnect the wires. At least I could put the chassis in a place where my wife wouldn't ask me every 5 minutes if I was putting it away. And lo and behold, on the right side of the board, on the three pins closest to the front, we had the white wire from the second pin disconnected.

So I unbraid it slightly from the red wire it was braided with, strip a little back, and bend the wire tight around the post. Voila. 100% functional. And this thing has some pretty serious power. Test run will be happening in the basement shortly. Wheeee! Maybe I'll need some help fixing my NAD.
 
Don't rely on the wrap on the junction post. Solder the wire on. Unless you have a wire wrap tool and new wire, and a new or cleaned post, the connection is very marginal at best.
 
Good deal! I am trying to figure out what wire you found disconnected.
I would still do the amp and PS board. This is not to hard to do.

Picture?
 
there are better ways to attach the wire .one way is use a proper wrap tool ..next is replace the pin with a solder one . next remove the pin and put the wire through the hole and solder direct to the board . last way is solder to the original wrap pin .
at the end of the day its what works best for you .
 
Will do - no time for the unit until next week, and will solder the wire on then.

Zeb, appreciate the suggestion, and may still do it at some point. At least it's functional for now for me to give it a good workout.

Again, best I can describe (sorry have the cover back on and unit is away) is with the unit upside down and the front panel facing me, there are a row of wires attached to the right side of the board. In the bottom right corner, the bottom pin has a red wire, second white, and third red. These are heavier gauge wires coming over from the big black doohickies to the right. (capacitors?). The bottom red is a lone wire, while the white and red for the 2nd and 3rd posts are braided together.
 
This are the main bus (rail) supplies to the power amplifier assembly. You really don't want an intermittent connection there since any surge from the supplies due to arcing could wreak havoc on the power amp components.

PioneerSX-950PowerSupplyHeatSinks.jpg


It may be best just to shut the unit off until a proper repair can be done.
 
Hey Watt,

You can barely see the wire that disconnected in the bottom right corner - white, second from bottom. So apparently, my issues were on the power bus, not the amp board itself.

Appreciate the suggestion. Unit is currently not plugged in, and not hooked to anything (ran out of time yesterday), and will leave it so until I get a chance to solder it. Have a feeling that I should really have better speakers to test this with.....
 
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