Question about a board from an amateur
Adam wrote 03/03/2015 at 12:31 • 2 pointsHello!
I have read HAD for years. I love the projects and creativity of the people around the world. I rarely mess with anything electronic at any sort of micro level. I hope this is OK to post here.
The other day, a friend of a friend asked me to look at a dead phone (Samsung Galaxy S4). The phone's power switch is messed up, as far as I can tell. I found a few sites and YouTube videos documenting the same issue and showing that replacing the power button will fix it. They already have a new phone, but they want a few pictures off of the phone. The pictures are not important enough to send the phone off, but they wanted me to give it a shot before trashing the phone.
I was able to pop the old switch off the board. I then started cleaning up the leftover solder. I put some copper desoldering braid on it to get the last of it up. However, as I was removing the braid, part of it stuck just a little bit. When it came off, a little pinkish square was attached to the bottom of it in the solder. It looks like a contact or something. The board, where there was a square solder spot, there is now a greyish square. Testing continuity there yields nothing.
I didn't hold the soldering iron on the board for a prolonged time or anything, and I didn't pull hard to get the braid off. It was all just one motion, but a little bit cooled before I pulled it off. So, I have a few questions:
1. Is my description enough to figure out what I am talking about?
2. If so, is there anything else I can do to recover from my position?
2a. That is, can I reattach something like that or am I screwed?
Sorry to throw out a dumb situation. I am just in over my head on something like this. The extent of my soldering experience has been on simpler projects with much, much larger working areas.
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I really appreciate all of your comments! In the end, I was able to power up the phone using the whole USB connection to a computer method. The pad I pulled off was the open side of the switch. I was going to try to scrape a little away from the board and try to get enough to solder to, but like I said, I was in way over my head. Before yesterday, I didn't even know I could power on the phone with a USB connection to a computer. After all of your comments, I did a lot more searching and came across an article that detailed it.
I would have had to remove the power button anyway, as the open side was closed and causing the issues in the first place, so I had that going for me. :) After reading all of your replies yesterday, I figured I could just remain calm and try a few things. When I got home, I put it all back together, used a spare battery, and tried the USB connection. The thing powered up, and I was able to recover everything from it. I figure I can classify it as a success with an asterisk. I didn't fix anything, but I was able to recover everything.
Hacker404, I tried the SD card immediately, but her phone was set to store everything on the phone itself. Had I not already read an article about the USB trick, your post would have given me new hope.
So, a huge "Thank you!" to all of you for your comments. I am going to go back to just reading HAD articles and leaving stuff like this to the rest of you. I can be happy just reading articles and acting like I understand some of it. If anyone asks, though, I knew what I was doing, and everything went according to plan. :D
Are you sure? yes | no
I haven't worked on that model. I assume that the pictures aren't on the SD card because you could just take it out and plug it into a computer. Most mobiles will power up when they detect a USB cord plugged in (when connected to a computer at the other end) , even if the face of the phone doesn't light up. If this phone does then you can just drag the files off that way.
Are you sure? yes | no
On a switch in particular I guess a square could be anything, but sometimes a square pad is used to mark a specific pin, such as positive for electronic capacitors. Since it's a switch, if you're in luck, that pad is connected to something large and easy to find and you could just jump-lead it over. Failing that, http://home.comcast.net/~machrone/bjr/mistakes.htm seems to have some illustrative shots for PCB lead repair without special tools, though it's certainly not for the faint of heart. YouTube appears to have a bunch of videos on the topic too, which might help.
Are you sure? yes | no
I suppose it depends on where it was connected to and whether you can find another place on that trace where you could solder a piece of wire...
Are you sure? yes | no
The desoldering braid stuck to the copper pad beneath it, and unfortunately it took the pad with it when you lifted the braid. This copper pad was part of the printed circuit board, and will likely be difficult to fix.
This is an all-too-common issue, but one without an easy solution. The pad, once gone, is nearly impossible to replace. However, there may be a workaround. On some boards you can clean off some of the colored (usually green) solder mask on the trace that the pad used to connect to and then bridge the solder from that to the new component. Other times you can solder a wire to a nearby pad that would have been connected to the lifted pad, and then solder that wire to the new component.
Either of these solutions are tricky to do if you aren't experienced at soldering. I've been soldering for 32 years and I would consider that to be a tricky fix. Maybe even impossible, depending on how the board is constructed.
Good luck!
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Thank you, Malachi! That at least gave me a place to start. I don't always know what I don't know, so having a starting point will be helpful.
If anyone else has anything, I would welcome it!
Are you sure? yes | no
Sounds like you pulled off a copper trace, no idea what it went to though.
Are you sure? yes | no