Not today, but yesterday I fixed an IBM PC 5150 motherboard in what was both one of my worst blunders and best successes in soldering... ever.
I got the PC with its original CGA monitor for $75 from someone about an hour away, and I intended to use it to test some other hardware from that era that I'd picked up to resell. It was a really good deal, even though I figured I'd need to fix something.
The monitor works beautifully, and the PC turned on without a hitch... well, aside from the hard drive squeaking like wet brake pads when it starts and stops, but that's not important. When going through POST the system would stop at a memory error, which when I looked it up online indicated a failure of the parity chip in memory bank 0. Now, keep in mind this is from the era of DIP socket memory, not sticks. The problem is, only banks 1, 2 and 3 are socketed, bank 0 is soldered to the board (so there's always a minimum of 64K...
). This meant taking a soldering iron to a vintage board (of which there are usually zero on eBay since they basically remained in their PCs, which sell for $200+ in working order) based upon Google search results alone.
Now, I don't solder that much. In fact, I find it really frustrating most of the time because things just don't seem to work the way I want them to. Whether my iron just wont accept solder or the solder on a board just WILL NOT MELT... one thing or another usually happens to make it frustrating. In the case of desoldering through-hole components, my problem is always getting the solder OUT of the holes.
Long story short, I fought with one of those irritating desoldering pumps that I've had for years while using a brand new (but cheap) 30W iron... since my old reliable 10 year old Radio Shack butane iron started smoking from the handle and I no longer felt safe using it. The old board couldn't handle my countless attempts and prodding, and the solder pads ended up getting mangled on the underside of the board on three of the 16 pins on the memory chip. I ended up buying one of the nifty (and cheap) desoldering irons from Radio Shack that have the solder-sucking bulb attached to the end so that you can just heat the part and suck it up immediately. While the damaged solder pads were beyond repair, this new tool allowed me to clear the remaining holes perfectly and I thought "hey, its loose! What's the worst that could happen if I just yank this off of here now?".
I pulled the chip off with ease... along with the innards of the three "stuck" holes and the copper traces from the surface of the board. YOUCH... that was sad to look at, let me tell you.
But, I was honestly just relieved to have finally gotten the stupid bad chip off the board. After a few minutes of sulking and calling myself stupid (a normal part of my soldering endeavors), looked at the board and thought "hey, they're just tiny flat wires and I can see where they went..." so I put the new memory chip on the board, soldered it (with ease), and then used tiny wires to connect the pins that should have been connected with traces.
To my complete and utter astonishment, it actually worked! The system booted up just fine and passed its memory test without so much as a single memory error, and I rebooted 15 times without any problems!
Now I just need to fix the keyboard I just happened to have that will work with this... and I'll be able to start using this thing to test some really old hardware. What fun!