Continuing the repair from last time, I'm still working on the GD-ROM drive. I received the surface mount radial capacitors and I need to remove the old ones and solder in the new ones. I have a lot of experience working with through-hole components, but very little experience working with surface mount components. There are several possible ways of removing surface mount capacitors. One common technique is to use a heat gun. I've even see videos of people literally pulling them off (no heat) - but this could damage the board.
I decided to try the two soldering iron method. Using two irons, you heat up both pins at the same time and then pull the part off using the irons. I borrowed a soldering station from a friend to use as the second iron. This method worked pretty good. I got all the caps removed with no issues.
Before installing the new caps, I tested their ESR. The 100uf/16V and 100uf/6.3V tested at .3 and the 47uf/6.3V tested at .7. These numbers are lower than the expected maximum in the chart from last time, and significantly lower than the previous values for the old caps.
Soldering in the new caps was more difficult that I had expected. It took longer to get the caps soldered into place. And with some of the caps placed close together, it was hard to get my soldering iron down on the pad. But I eventually got then all soldered into place.
I reassembled the GD-ROM drive and tested the system. Here's where I got the bad news. It will spin the disc, and the laser lens will move up and down trying to focus, but it will not move the laser assembly up and down the track. This tells me something is wrong with the GD-ROM drive, it's not even seeing the disc so it won't try and read the tracks. This is a loss of functionality. Before replacing the caps it would move the lens and could at least ready music CDs. But now it won't ready any disc.
So I must have messed something up. Perhaps I created a short when soldering on the news caps. I need to remove the circuit board and have a look under magnification. It could be something as simple as the ribbon cable not seated properly. And if all else fails, I may remove these new caps and replace them with through-hole capacitors which are easier to solder.
All that said, this Dreamcast is actually on the back-burner for right now. I managed to get my hands on a second Dreamcast. This one also came from eBay for $5. It's the rare black USA Dreamcast including the controller. It was listed as "broken" because it made a loud noise when you turn it on. I've already found and fixed the problem. The lens assembly moves back and forth on two metal rails. These metal rails are held in place by screws. One of the two rails popped out of place. I put it back, secured the screw, and now the system works perfectly. It read game discs, music CDs, as well as burned CDs such as DreamShell.
This new Dreamcast is going to be the system I mod going forward. At some point in time I'll come back to this white Dreamcast and attempt to finish the repair.
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