There have been two motherboards for the Solidoodle historically. Generally, neither one of them has deep problems. Most problems attributed to the motherboard originate in other hardware on the machine. That said, there are a few unique motherboard related problems
The Sanguinololu (as opposed to the current "Solidoodle Motherboard") suffered from overheating issues in a small number of users. In general, the issue could be fixed with the addition of a small fan. Current motherboard iterations do not exhibit this issue, and the majority of the older motherboards did not have the problem.
Stepper chip failure
Rarely, the stepper chip will fail. This is typically due to improper handling of the chip itself, or to factory defects. In most cases, a factory defective chip will simply exhibit a short life span and cease to work after a few days of good operation. This was a larger problem in the Sanguinololu days, as the chips were more directly exposed to users than in the current design. For users with the Sanguino boards, the solutions was to swap out the chip itself. For users with the Solidoodle motherboard, stepper chips must be repaired at the factory - they are SMD soldered and therefore not easily repaired at home.
- Diagnosing Chip Failures
Typically, after a chip fails, functionality of the associated axis will be lost. It is not unusual to see a period of reduced functionality just before the failure. A quick way to check that the issue is the chip, and not the motor itself (which is far less prone to failure than the chip) is to switch the cables for the motor to another chip. If the chip drives the desired motor, then we know that the chip is the issue, and not the motor. However, if the motor does not move the next likely candidate is the cable, the crimp, and finally the motor itself. Solidoodle has only seen a handful of stepper motor casualties in the last few years.
At a few points in the history of Solidoodle, we have had customers show us boards that were shipped sans bootloader. Typically this isn't a problem, since the boards do not necessarily need a bootloader to operate - just to upload firmware. If you have a board that you think does not have a bootloader, and you would like to reflash your firmware, the best bet is to burn your own bootloader via an AVR programming cable.
And those are about all the errors that are fit to print!