I did not get from the automatic translation that you have a tower case with lots of extra stuff in the computer.
A DC-DC converter for the 5V of RapidRoad may really do the trick, if it starts up fast enough. The key would be that the 5V of the DC-DC converter come up at the same time or before the 5V of the main computer. If the 5V rail of the PSU comes up before the 5V from the DC-DC converter, you may see latch-up again.