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Full Recap or Partial ??

Califmike33 said:
He just put extra parts he told me by mistake, there are no other 22uf caps. I will get back to work, funny thing is this new SA 300 looks like it had work done, i can tell by the bad soldering job, but i have replaced parts and it works fine. Now i will keep going, really getting the hang of soldering.
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Sounds like good progress... and the fact that you're becoming practiced enough at soldering to critique previous work is great progress!
Bravo to you for having the patience to step back and hone your skills!
 
Thanks, yeah im really enjoying it, i have had a few problems taking things out, but i have figured how to do that, and no burned tracers yet.
 
Well i put in a 1685 and soldered all three leads, but i think i jacked up a tracer, got it to hot, but seems to be still working so leaving it alone. Problem im having is the balance knob when turned doesnt switch left to right in my headphones, and when turned to the right all the way just cuts all sound out. I have no idea whats going on, i cleaned the balance switch and same problem.


Anybody have any ideas why the balance knob is acting like a volume knob, when turned to right balance it just stop sending any sound ????
 
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So I've got most of the board recapped but can't figure out what's going on with the balance.

It's not the switch itself because I cleaned it with air and detox still does the same thing so I don't know enough about just to know if switches can go bad and cause what's happening or if somebody was messing with this thing before I got it cuz there are places where it's been soldered I can see and screwed it up.

I do have my old board that I could take to balance potentiometer off of that and put it onto the new one but I believe I'd have to unsolder it and see if that fixes it
 
A balance pot works sending the signal to ground. Check the schematic. Check the wiring and if the pot is the right part. Also check (sending2 different signals to L and R) if you hear both channels, because I've seen amps with bridged channels, one channel not working and one channel connected to both speakers.

Compare both units to see if you find some error in the wiring or connections.
 
Well after checking, i have no right channel at all , its dead only left is working. Ohhhhh boy problems, i doubt its from what i have changed as far as caps.
 
vinnysj said:
Build a DBT if you don't have one. It will save you when you make a mistake.

Please double check. Don't trust me.

For the capacitors,
2x 470uF 63V -- C707, C413
2x 33uF 50V -- C611, C612
2x 47uF 50V -- C613, C614
2x 100uF 50V -- C617, C618
2x 100uF 25V - C403, C404
3x 1uF 63V -- C601, C602, C625
2x 3.3uF 50V -- C401, C402
2x 0.47uF 100V -- C411, C412

For the transistor, don't change them now. I would keep them as is for the time being.
KSA992, two of them will replace one of Q601, Q602
Click to expand...
vinnysj said:
Build a DBT if you don't have one. It will save you when you make a mistake.

Please double check. Don't trust me.

For the capacitors,
2x 470uF 63V -- C707, C413
2x 33uF 50V -- C611, C612
2x 47uF 50V -- C613, C614
2x 100uF 50V -- C617, C618
2x 100uF 25V - C403, C404
3x 1uF 63V -- C601, C602, C625
2x 3.3uF 50V -- C401, C402
2x 0.47uF 100V -- C411, C412

For the transistor, don't change them now. I would keep them as is for the time being.
KSA992, two of them will replace one of Q601, Q602
Click to expand...

I think something is off on this list maybe, i could be wrong. The 2x 100uf 50v doesnt look like it goes in c617 , c618, . When i look at the board in those slots those are completley different parts, they look like they go in C615, C616, im kinda stuck im not sure about this .
 
Califmike33 said:
I think something is off on this list maybe, i could be wrong. The 2x 100uf 50v doesnt look like it goes in c617 , c618, . When i look at the board in those slots those are completley different parts, they look like they go in C615, C616, im kinda stuck im not sure about this .
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If the board is original, always follow what is installed on the board.
 
Ok thanks. What is 100 p that what's on the service manual now I know if it says 50v 100 that's a 100uf 50v. But the two spots I'm talking about just say 100 p which doesn't seem to match the 50 volt parts there's no voltage mentioned and I don't know what the p stands for.

And the parts look completely different from each other.
 
100p is 100 pico farads (pF). In such a small value, it's likely a ceramic capacitor and they usually do not need replaced. However, I do find some in tone networks, and have been replacing those with new Multilayer (MLLC) C0G/NPO ceramics which typically have better temperature stability and lower noise than “standard” ceramic caps. I typically use 100V rated for these which covers most of the equipment I’ve been working on.
 
Thank you didn't know what it stood for but you're right it's a ceramic capacitor and the parts in the bag are electrolytic so it doesn't go there it goes where I thought it went and the listing in this thread of where it goes turned up to be wrong everything else on his list has been spot on this one is actually wrong and I confirmed with the person that I bought all the parts from that where I want to put it is the correct spot.
 
Well I got 95% of the recap done only burnt one tracer out of all of it should finish it tonight then I got to figure out what's going on with the Left Right channel if I can figure that out. Have to say I've learned quite a bit from doing this process the next unit should be a whole lot easier I would think.
 
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