The various soldering guides usually don't allow for printed circuit boards that have been damaged by hot components and such. This is probably what you have going on. I have not seen the particular board you have, but I have repaired a LOT of pcb's that have been damaged in one way or another and the tricks are:
Get the old solder out. Use solder wick or a solder sucker (real name, look it up) or maybe a bit of compressed air. In all cases, be careful of the old solder getting away from you and splattering some other component. Look closely for bits of it.
Get an exacto knife or some kind of small hobby knife and scrape, yes I said scrape, the board to remove the burned debris. You want a clean untarnished surface. This may mean scraping away some of the paint that protects the copper traces, but that doesn't matter right now. If there is a pad, this is a round enlarged area in the copper trace, scrape some of the paint away from it and expose the copper underneath. Be gentle doing this you don't want to saw at it and cut through the trace.
When you have a nice clean and enlarged area get some rosin and smear a little bit of it on both sides of the board covering the area you just scraped.
Put the new component in place and, using LEADED solder, heat the joint enough so the solder flows completely around the component. Yes, I know I'm not environmentally friendly, I'm trying to fix something and save myself some money, not worry about a tenth of a gram of lead poisoning some rat someday, besides, there will NEVER be a baby chewing on this. Oh, use a thin solder, not that stuff they sell at the hardware store to use on 3/4 inch copper pipe. You want something 18 gauge or less, a couple of millimeters or less in diameter.
Inspect your work and make sure the solder joint is minimally reflective, not looking like a fractured mess. If it is a fractured mess, you moved it before it cooled enough or you heated too hot and boiled the tin out.
In some cases, there is a metal rivet in the hole. Some manufacturers do this for components that get a lot of heat. If so, make sure the rivet is secure and well soldered.
If you do it correctly, you will have a new solder joint that is larger than the old one and probably twice as strong. Use a soldering iron, not a soldering gun. Those Weller soldering guns were designed in the days when we were using #16 wire and tying it to large posts, way too much heat for something like this. A 40 Watt iron that runs around 700 degrees F would do the job fine.
You can fix this yourself, have fun and enjoy it. If you have too much trouble, post a picture of both sides of the board that shows what you're up against and maybe I can suggest something.
Before you power it up check again for stray solder and solder that may have sneaked over to some other trace making a short.
Then, you should be good to go.
