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Full Recap or Partial ??

Thank you very much appreciate it already did that they look perfectly fine they're connected the little wire inside the fuse is not broken.

Went to the electronic store bought myself some PCB board and some transistors and caps going to practice my soldering.

No one old guy that works there told him my situation he did stereo repair for 15 years told me to bring the schematic in it'll take a look at it and see if he can help me out he said he wouldn't dare take it in and pay them to fix it it's not worth it.

So I think between all you kind folks on here and him looking at the schematic I think we can get this baby running again.

He did say check all of your solder joints make sure your solders are good double triple check them that's the first place he'd start which you guys have recommended which I'll do again I don't have to think that's the problem but he said to make sure all the negatives are facing in the correct direction which they are but I'll double check that again.

And he told me to listen to it when I turn it on and see if there's a click if the relay is working he says if you don't hear the relay you got a little more trouble than you might have thought you had.

Again appreciate everything I'm determined to get it working again.
 
Think I found the problem when I was moving this capacitor it's one of them that I soldered in it started moving the one pin and you can obviously see that the trace is gone this might be the whole problem right here.
 

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If you just replaced 6 capacitors, it should be easy to undo your work, pay attention to wires you had to bend or disconnect to access the boards. Check nothing is shorted or disconnected, or a screw pressing some wire to the chassis. Remember to do a mark on the capacitors facing all to the same side. I always mark the side pointing to the front of the unit, so I can check the new part was fit the right way.j

ALWAYS CHECK THE UNIT IS UNPLUGGED, REPEAT TO YOURSELF "UNIT UNPLUGGED" AND CHECK AGAIN. Electricity don't give second chances very often.

I'd also think again about starting a recap on a working amplifier. You are seeing is not that simple the 1st times.
 
Yes, the pad you showed in your last picture is blown. You will need to run either a jumper wire from the leg of whatever component goes in that hole to the next one along the trace, or, as shown previously, scrape away a bit of the green lacquer along the middle of the trace, and bend the leg of the new component so that it touches the bare copper you just exposed by the scraping. Solder the leg to that and you should have good continuity.

here's what jumper wires look like when solder pads have been damaged….

https://audiokarma.org/forums/index...of-the-solder-pad-lifts.782571/#post-10760845
 
Thank you for that. My current amp is now a full on practice amp, im de soldering and taking out caps and then putting them back in to solder again till i get good at it. I see it dont take much heat to fry that tracer. I have been watching some videos on soldering. I found another unit working on ebay for cheap, going to use my face plate, knobs etc and use the other board. Im removing every transistor, cap in my current board and resoldering back in for practice. Watched a video the buy never really desolders it, just heats it up wiggles it back and forth and out she comes, the puts new on in re heats the solder. Its been a real exp and eye opening , but im enjoying it. Im practicing trace jumpers the whole 9 yards to prepare for when my new unit gets here.
 
I got my newish bench going, I'm finishing my 4th older amp, I scope test them, and if they read well, I don't bother (so far). Mind you some of the repairs (most) have wound up being a cap in the end, I just replace the R&L pair of the defective one that I find.
 
Califmike33 said:
Thank you for that. My current amp is now a full on practice amp, im de soldering and taking out caps and then putting them back in to solder again till i get good at it. I see it dont take much heat to fry that tracer. I have been watching some videos on soldering. I found another unit working on ebay for cheap, going to use my face plate, knobs etc and use the other board. Im removing every transistor, cap in my current board and resoldering back in for practice. Watched a video the buy never really desolders it, just heats it up wiggles it back and forth and out she comes, the puts new on in re heats the solder. Its been a real exp and eye opening , but im enjoying it. Im practicing trace jumpers the whole 9 yards to prepare for when my new unit gets here.
Click to expand...
Try solder wick, a sucker can damage the pads/traces unless you are very delicate. I dont like the idea of heating and wiggling unless you can hit all pads at the same time, otherwise when you push/pull/wiggle the pad that is not being heated takes the force and can again unnecessarily damage or lift the pad, then it is another repair of the trace, for what?
 
Well in my short exp i do prefer wick, and acually tonigh doing the wiggle and remove i did lift a trace so your right. I think i will stick to using wick and then just solder, i had sacrifice my current amp for learning process, but now i have a good practice piece with spare parts.
 
Technics = replace everything, even if they measure good, matsushita/panasonic tend to leak over time
NAD = replace everything, they allways used crappy capacitors
Krell / Mark Levinson and any other that used Sprague capacitors = replace everything
Also replace all other crapy brands like jamicon, teapo etc...
Elna duorex = replace even if they measure good
Old Nichicon Muse are excellent capacitors in sound terms but they have short life, 30 years old capacitors will have about half of their nominal capacitance, rest of the old capacitors are usually ok

All the high end stuff mostly used top of the top capacitors, in that case measure and then decide.
 
Here are a couple of video tutorials about soldering and tools
This fellow knows what he's doing. (He's an electrical engineer.) I would highly recommend watching his technique carefully and also paying close attention to his selection of tools and materials, then practicing until your soldering looks as good as his. (It really isn't that difficult, and he spells it out very clearly.)

A couple of tricks to make soldering of small components on a crowded PCB easier, are to work under a good bright light and use magnification to be able to see your work more closely.

If you hone your soldering skills (and make a dim bulb tester) prior to beginning to work again on anything you care about, you'll be in much better shape to complete any work properly.
 
Thanks for the soldering videos they look good and im watchng them, LOVE HIS SHIRT I ONLY GIVE NEGATIVE FEEDBACK. Will be making a dim light tester today.
 
When desoldering, don't "wiggle back and forth", that is what damaged the trace. You need to melt the solder and PULL from the component side, never push to the solder side. The traces can hold some heat, but not heat + pressure + movement. Always pull the component. Adding fresh solder helps. Heat the solder without pressing on it. You need heat, not force.
 
As far as the dim bulb tester goes I've been watching some YouTube videos and getting some mixed ways of doing it for number one does it need to be an incandescent bulb? And what what bulb would I use?
 
Got another sa 300 on the way going to use the body of my current one but use the boards on the other one and do the recap going to keep practicing and practice and practicing to my soldering gets decent before I attempt to recap the one that's coming.
 
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