Pioneer sx1010 took a crap

[ingola]

Is this the best way to do this

 

[larryderouin]

Can you take a picture of the back of the AWH-032, where the lifted trace is. Your description sounds good but a Picture will fill in the 1000 words. Oh BTW asitone is actually spelled ACETONE.

 

[ingola]

Stupid spell check. Here is the back you can't really see it I noticed when I gave it a wiggle. Please note I have gotten another soldering iron since the one I had was burning the boards

 

[larryderouin]

I think you're keeping the heat on too long. No more than a count of 4 and you should have liquid solder joint. If not apply some electronic FLUX Paste to the joint, then reheat for a 4 count and suck it up. You will also need to keep your tip clean. one of those brass stranded ball in the kitchen supply aisle works wonders. Don't get the plastic one, get the brass one. Dollar Store has them for $3.00 IIRC, all the electronics stores sell the same thing for $9.99 to 13.99. Some people are just suckers. Dip the tip thru the brass each time you pick up the iron, then tin it.

 

[ingola]

Ok reflowed all the joints bias will still not move above 8.7 when I measure the offset I get nothing no infinite I worked all weekend first time I had a chance to look at

 

[ingola]

Here is what I'm getting

 

[zebulon1]

That's the DC Balance your checking? Pin 19 and chassis ground.
Meter is set to mV's. Select DC volts and let the meter auto range.
Is the amp railed? Looks like it.
Recheck the Idle and Balance procedures.
Outputs are probably good.
It could be you installed a transistor in backwards. The TO-126 package (square) is easy to put in backwards. If not retesting the transistors for condition is next.
Double check the placements before getting kooky.
Take your time. This is the point where you need to really take care in your work. The old crusty set can only take so many swipes. Look for broken wire wraps, double check your work before applying power.

Don't get frustrated your doing well and learning.

 

[ingola]

What do you mean by railed? The idle is at 8.7 still will not change at all. The DC is at infinity. The left side is dead on spec it's like there is no current getting to that pin

 

[ingola]

As for the dimmer switch nothing is wrong with it I had one cap on the power supply board backwoods causing the fuse to blow. If a transitor was in backwards would it have ran for the 25-30 mins first before this all started ?

 

[ingola]

Yes it's DC I'm checking

 

[zebulon1]

I'm going by the image you posted.
Your right about running it, so it must be a bad driver causing the railed condition.

 

[ingola]

Bad driver meaning what?

 

[ingola]

The reason I checked the DC again is I read the protection circuit trouble shooting guide it said the idle current was high the protection circuit would kick in but it's not high it's low so it would have to be a problem with the dc balance am I understanding that correct I've done smaller units before this sx1010 is a whole other beast lol

 

[zebulon1]

I think the DC Balance check will reveal high DC voltage on pin 19.
If it does, then one side of the amp has overrun the voltage on the other side.

The meter looks like the voltage setting was set to low.

 

[ingola]

It's set at 200m is that two low

 

[zebulon1]

Yes
The amp is is not it conformity
The voltage is set to low to see what's there. It would be fine if the amp was behaving.
Follow my request to recheck the DC Balance using a higher voltage setting on your meter.
You might be seeing near 50 volts.

 

[ingola]

Ok where should I set the meter.. I'll check it when I get home, I will check just that and get back to you.. you know it's a testament to yours and other members skills how your able to walk a relative newbie through a reciever 2000 miles away it never fails to impresse me

 

[ingola]

Ok changed the setting to 200v and you were right it the dc is high turned pot will not change

 

[zebulon1]

What was your reading?

 

[ingola]

It's in the photo 38v