Is the issue you are having the physical outs not working, or the bus not passing signal no matter where you patch it for an output?
If it's the signal not passing, one thing to check is make sure the bus wasn't assigned to a DCA. I've seen people get bitten by that more than once. Everything seems great, but the DCA is down, and you lose whatever is assigned to it.
The fact that you're saying it's outs 1-5 is pointing more towards a config or patching issue, since hardware issues would more likely mess up groups of 4 or 8, not specifically 5.
If all else fails, have you tried a full factory restore of the board? Sometimes you can miss a setting and a factory reset gets you to a known starting point at least.