First time soldering, does this look ok? - Page 1
Forum section: electronics / beginners

author: doodle43
author_rank: Newbie
timestamp: August 19, 2020, 11:58:14 am
content: I finally got around to replacing the capacitor in my Samsung TV. And it works again! It was my first time soldering, and I just want to make sure I did ok because I had some trouble with it. The photos are of three different stages, the last being the final one.First I had difficulty desoldering the original, lead-free solder. It took a lot of heat and I don’t think I got it all. The pads are a similar silver color so it was hard to tell if I got every last bit. Is it ok if there remained a little bit of the old lead free solder when I added the new leaded solder on top?The PCB turned brown around the area I worked. Did I burn it or is this flux residue? I cleaned with a little isopropyl alcohol after but it was still there. Will this be a problem?I also think I used too much solder, especially the left one. I was happy with the amount in the first picture, but they looked cracked to me so I added more. I also reflowed them a few times after cutting the leads because I thought it still looked off. I should have stopped at photo 2 but I added more solder after that to the left one. I think the reflections were throwing me off and making me think there were cracks when there weren’t.I really don’t want to have to rework these joints again. And the TV is working. But I’m feeling paranoid about it. Do you guys think the joints look passable or will I have trouble in the future?

author: tggzzz
author_rank: Super Contributor
timestamp: August 19, 2020, 12:13:05 pm
content: I've seen a lot worse.Many people like these old but succinct videoshttps://www.youtube.com/playlist?list=PL926EC0F1F93C1837N.B. I dislike videos, except where they are better than the alternatives!

author: SmokedComponent
author_rank: Regular Contributor
timestamp: August 19, 2020, 12:39:34 pm
content: That will do.Reflections are good, it is because of proper leaded solder, unlike crusty old lead-free stuff.To get rid of the old solder you actually need to add fresh solder, so it mixes with the old, making it melt much easier. Then you suck everything away and clean pads with solder wick.You need to rub burnt residue a bit harder (with alcohol soaked cue tip or conductive brush) to get rid of it. If it is no longer sticky, in this case, I would leave like it is rather than bother with harder stuff like acetone.

author: doodle43
author_rank: Newbie
timestamp: August 19, 2020, 12:48:54 pm
content: I actually watched those exact videosBut I realize that I could have done a better job if I had some actual practice first before tackling my TV. So you think these joints will hold up ok? If it’s not gonna break over time or catch fire or anything I’d rather leave them be, because I feel like I overworked them.I used a pump to desolder - didn’t have any wick. Is the flux residue harmful if I left it?

author: thikone
author_rank: Contributor
timestamp: August 19, 2020, 01:04:45 pm
content: Looks alright, but... it seems like you had to heat it a lot before it could stick to the wires and there is some strange dark circle around wire.I usually clean the wires with rubber eraser (it has some particles in it) that can remove oxidized layer (wire becomes more shiny).Or even tin it before soldering on. Start tinning at the place near the part and then move iron to the end. This way if it will not go though because of tin ball at the end, you can simply cut it out and there will be still enough wire left to mount the part.

author: doodle43
author_rank: Newbie
timestamp: August 19, 2020, 01:22:32 pm
content: Im hoping those dark circles may be another reflection. The leads were covered in solder, since I reflowed and added more solder after cutting them. After that it looked like little solder nipples on the top.