Your solder connections don't look good. I wish I knew how to access the soldering instructions that I posted on the forum!
Does anyone know how? We should make it a sticky.
Anyway, your solder connections are blobs. That means you didn't heat up the connection, for a few seconds, prior to applying solder. What wattage soldering iron do you have?
Get a solder sucker, heat up the connection and push the button (after compressing the spring) on the solder sucker while pressing it against the molten solder.
Make sure to use electrical solder and not solder for copper pipes, etc. Use rosin core, with tin and lead. Lead is safe if you don't inhale the fumes. I've soldered since age 6 to my current age of 62 and no lead poisoning. My sister did stain glass work for a few years and she tested positive for lead!
Solder suck the solder off of the wires. Assuming your soldering iron tip was tinned properly wipe it on a wet sponge with 90% of themwater squeezed out. Do not have wrap the sponge around the tip, let the sponge lay flat, then wipe one side, then the other side. Do this before and after soldering.
But, first make a mechanical connection first. If it is a printed circuit board (PCB) heat up the wire and then apply a small amount of solder to the wire, NOT the soldering iron. The wire should be stiff, without a blob. Push the wire into the hole, turn the PCB over and bend the wire so it will stay put.
If the PCB has a foil ring around the wire hold, press the iron's tip on the ring and press it against the wire. Let it heat for a few seconds, then apply the solder to the wire, next to the PCB a but not touching the iron's tip. You should see the solder being 'sucked up' the wire an onto the PCB a ring.
The joint should be smooth shaped (no blob)'and it should appear shiny. If it looks frosty, you have a cold joint, if it is a blob, you may not have waited long enough to apply the solder. Other causes are a tip that wasn't tinned to begin with or your soldering iron's wattage is too low. A 45" watt iron is good for this king of work. A variable soldering iron station, with different tips, will allow you to solder most anything.
Okay, if the PCB has a ring on the underside of the board, check to see if the wire is soldered good. If not, add some solder there. There are special wire snips for this, but get a wire cutter and cut the excess wire off. Make sure there are no sharp edges, if so, trim them off.
In case you need a new tip, buy a medium chisel tip if your iron has adequate wattage. Let the tip heat for several minutes. Wipe both sides of the tip on the wet sponge and immediately apply a very generous amount of solder. It will smoke, don't worry about that. After about 20-30 seconds, wipe the tip on the sponge. You should have a shiny tip all over the tip. If you wipe on the sponge, it will stay that way for a long time. Buy a new tip when solder won't melt on the tip.
That and tinning are the only times that solder should touch the tip.
p.s. I hate Radio Shack soldering iron's! Buy a Weller and if you plan on doing a bit of soldering, now and then, buy a Weller variable wattage soldering station with a soldering iron holder and a sponge and its depression. I hope this helps.
p.s.V2. After reading the other posts, I have something else to add. Using tweezers or another tool to hold the wire in place while applying the iron and the solder causes two problems: First, you run out of hands! More importantly, the tool used to hold the wire down acts as a heat sink. This makes it hard to heat up the connection and it can easily cause cold soldering joints. Since you don't have enough hands, people resort to putting a lot of solder, on the tip and then applying that to the joint. So, that is why you bend the wire on the underside of the board. If it is a terminal connection with a hole in the center, insert the wire into the hole, bend it back around with needle nose pliers.
IF you have just a solder pad (no hole) to solder to and a wire to solder to that, that is where a great tool, with many names, comes in. It will hold the wire, higher up and you just solder. If you want one, msg me and I'll find a link. BUT, if you have no one to help you, use needle nose pliers to hold the wire up higher on the insulation. With enough practice it is possible to hold the pliers and with the same hand, apply the solder! Use the palm of your hands to hold the pliers in your hand and use your thumb and index finger to apply the solder.
Whew! I think I covered it all - again. We really should make a sticky of this. How is that done? The first one might be best, I don't know.
Well, this could use a lot of editing, but I hope you got the message!