Dreamcast Common Fixes
There seem to be quite a few common problems with Dreamcast consoles, the most common is it randomly resetting itself. It should be quite easy to fix, and all you'll need is a screwdriver. Take the modem off, and undo the 4 screws on the bottom of the console, then take the upper half of the case off (make sure you've removed any discs). On the left hand size of the console you'll see the power board, at the front of the power board you'll see a plastic plug with 6 pins sticking up, these pins come up through the power board from the motherboard below.
Now it's time to remove the power board, unplug the connector at the rear, then undo the 2 screws (one near the front, one near the back), around the middle of the picture below you can see a small plastic grip holding the board, you'll need to pull this clip out to be able to pull the power board up. Be careful, only touch the edges of the power board, don't touch any of the components just in case of causing damage (to you or the console).
Once you've got the board off, you can see how long the pins really are. Push the pins towards the rear of the console, push quite hard, but don't push so hard that you bend them though.
You could also give the pins a little clean, that may also help them get a good contact with the connector on the power board. On one console, mmmonkey even melted a tiny amount of solder to each pin, this made the pin a bit fatter so it got a much better contact with the connector.
While you've got the Dreamcast in pieces, you should also check the other cause of random resetting. In the top right of the console, behind the GD-ROM drive, there is a small lever which detects whether the lid is open or not.
Check this lever for any obstructions, blow out any dust etc and make sure it's moving easily, also check the lid to make sure the bit which pushes the lever looks okay.
mmmonkey first read about this trick on the forums at DC Emulation. It's worth visiting the forums (in particular the hardware FAQ) if you've got any problem with your DC.
Many thanks to AndyB for passing this info onto me, I haven't had a chance to try them out yet but thought I'd put them here for others to try if they are stuck.
If your controllers aren't working, then it's likely that the fuse is blown on the controller board. It's easy to find, you'll have to remove the top of the console case, remove the power supply and then the controller board. The fuse is located right next to the rechargeable battery. It's labelled R1, and it does look like a resistor, but I have been assured that it is a fuse - 390mA picofuse. If you can't find a direct replacement then you can use a 0.5a like this.
The Dreamcast is fitted with a Rechargeable CR2032 battery, as with any rechargeable battery it isn't going to last forever and over time it may not hold it's charge for very long and you'll find yourself continually setting the time and date on your console. This is a direct replacement for it, you can't get much quicker and easier than that!
Finally - you've probably already heard of pot tweaking, a lot of people do it to bring life back to CD/DVD lasers and make them read discs again. The Dreamcast is no different and the pot can be found on the underside of the laser where the ribbon cable connects. Before turning this make a note of it's angle and then, very very gradually turn it clockwise, and I do mean gradually. Keep testing it after each gradual turn to see when it's working again.
