The new fiber arrived today, and we tried it out. No luck. We think it is the timing card, so we'll need to get one, since we can't find a spare.
Order of operations:
* Lay new fiber on floor, plugged it in at both ends, saw no fiber link lights.
* From control room, killed all models running on c1iscex, shutdown computer. Still no link lights.
* Power cycled computer and IO chassis.
* Tried plugging new fiber into different port on Master Timing Sequencer, with other end still plugged in to c1iscex. Still no link lights.
* Looked around with flashlight at Xend IO chassis. The board that the fiber is connected to does not have a power light, although the board next to it has 2. We compared with the SUS IO chassis, and the board there with the fiber has one power light, plus the fiber link lights, as well as 2 on the board next to the fiber. So, perhaps there's a problem with power distribution on the timing board at the Xend?
* Unplugged and replugged the power connector to the timing board, inside the IO chassis, board next to the fiber's board got lights back, but the fiber's board did not. However, power must be going through the board with the fiber attached, to the next board, so there's power at least on some part of the timing board, just not the whole thing.
From this, we conclude that the blue fiber that was in place is probably fine (or is not found guilty), and that we need a replacement timing board. Koji didn't find one in the "CDS stuff" boxes underneath the Jenne Laser, and I feel like I recall Jamie saying that we would have to get a spare from somewhere else. We rolled up the new spare fiber, and put it in the box with other "CDS Stuff" under the Jenne Laser table.