I've had a Samsung Captivate for nearly two years now and I have really loved it. The Android OS is incredible and the Captivate was one of the first phones to really excel at using it. Over time, however, it has begun to slow down as you'd expect. Certain apps are not as responsive and sometimes need to force close. I had a few problems with particular apps not working at all, which I found fairly frustrating. So, I thought it might have something to do with not having the newest version of Android for mobile phones. About a year ago I had flashed my phone from Eclair 2.1 to Froyo 2.2 and loved the new experience. It was quite easy to flash, so I figured it wouldn't be too hard to now go from Froyo to Gingerbread. Well, not as easy as I thought.
The first thing you need to do is download the newest version of Odin. The newest one I could find that's easily downloadable was 1.85. Unfortunately, this only works on Windows, so I had to do all my flashing on my Boot Camp partition. I also needed to install drivers for my Samsung Captivate on my x86 Boot Camp partition. Then, you need to flash updated bootloaders to your phone. Initially, I downloaded some bootloaders that must have been old or untrustworthy because when I tried to flash them Odin froze on the dreaded sbl.bin error and bricked my phone. I tried to unbrick this using OneClickUnbrick, but this only made matters worse. By this point it was 1:00am and all my phone would do when I turned it on was cycle the "phone exclamation point computer" screen over and over. It seemed like no matter what button combinations I pressed I couldn't get it unbricked.
The next day I knew I needed a phone and it seemed like I was going to have to get my Captivate repaired so I dropped by AT&T to see what my options were. Fortunately they now sell a $20 dumb phone called the U2800a that turned out to be pretty laughable but fairly operational. They also throw in a microUSB cable and wall mount though which makes it a great deal. Unforunately the phone has no drivers and there's no way to sync or import contacts or calendars, despite Google's great efforts to make this universal (you get what you pay for). So, this frustrated me quite a bit and I took a last chance stab at trying to get my phone into download mode. That's when I found a helpful tip that saved me completely.
If your Samsung Captivate is soft bricked and cycling through the "phone exclamation point computer" screen, and it seems like there is no way to get it into download mode, try this: 1) unplug and turn off the phone and take the SIM, SD, and battery out. Wait 10 seconds to let it completely cool. 2) Open Odin 1.85 and plug your USB cord into your computer. 3) Plug the microUSB end into your phone. 4) Press down all three buttons and while holding put the battery in. 5) Let go of only the power button. That put my phone into download mode and I was so relieved.
I found better bootloaders and a helpful video from MobileTechVideos. That guy really knows what he's talking about. I used his bootloaders to flash the phone again and it booted! Now I was back to where I started but with new bootloaders. I then tried flashing the kernel he suggests, but it didn't work for me. That's because my phone had already been updated to Froyo 2.2. Thus, I needed the speedmod kernel. I flashed that kernel, entered recovery mode, loaded a custom ROM via the mountable USB, and applied the zip install. After about 5 minutes it installed and I was up and running with a new ROM! I decided to go with a custom 2.2 ROM instead of Gingerbread for now, but this should work with a Gingerbread ROM as well, and I could still enter recovery mode and do that at any point. My phone is old, and I'm not sure what kind of demands Gingerbread would have on it. Plus, I had heard good things about this custom ROM, called Serendipity.
I like it a lot. The theming is slick, the response time is fast, and it even made my 3G much faster. All my apps work and I haven't had any force closing (except for some trouble with Swype). To get Swype to work I had to uninstall the built-in version with Titanium Backup and download their beta from their website. In a way, this was a good thing since I got the newest version of Swype. Flashing does void the warranty, but that doesn't matter for me because my warranty is already voided. The guy at AT&T had no idea what I was talking about when I told him how I'd bricked my phone. It's amazing how much some people know about these phones; I'm only grazing the tip of the iceberg.