Found h2susb78 locked up as of 21:02:43 PDT Aug. 28. Restarted, models ran about 3 minutes and communication between IOC and computer went away (one-stop card/cable issue). The IOC one-stop card was replaced with a new revision C2 card yesterday, so suspecting an early failure, the IOC one-stop card was replaced with another one. With this second new one-stop card, one of the main PCIe buses was not visible to the computer, and the duotone timing was off by 35uS. Gave up, and installed an old non-updated one-stop card back in the IOC. System came up normally, but will have to run without problems for about 3 days before confidence begins to be restored.