Sun Fire V1280
This machine is a bit of a beast. Fully populated it has 12 UltraSPARC III CPUs, 96GB of RAM and a weight rivalling that of your local Indian elephant. With these impressive figures in mind, I now tell you that it is the lowest end machine in the Serengeti range of machines. Its bigger brothers and sisters include the 4800/4900 and the 6800/6900. In addition it shares a lot in common with the Starcat systems: the Sun Fire 15k and 25k (a herd of Indian elephants).
Over in our second lab we had a sick 1280 that was throwing all sorts of errors during the power on self tests. Months ago I spent some time looking into this and came to the conclusion that none of the system or repeater boards were faulty. By process of elimination (I could have said Sun Global Resolution (SGR) here; it’s the same thing) I came to the conclusion that we had a faulty baseplane.
The V1280 is quite different from the rest of the Serengeti and Starcat systems in that it was designed primarily for the telco industry (the Netra V1280). For whatever reason, the engineers decided to orient the boards vertically and as such the V1280 is equipped with a fairly unique ratchet mechanism to support boards as they are being inserted into the chassis.
Anybody who has ever dealt with a 1280 will know exactly what I mean when I say that the first time you install a board is a memorable experience. The ratchet system is very effective in supporting the load, so much so that to get the board down into the chassis requires a fair amount of force… all very well good until you find out (at the cost of your system board and baseplane?) that the ratchet system stops about an inch before the bottom of the chassis. This discovery is usually accompanied by a loud crashing sound and potentially a hefty repair bill.
That said, I like this mechanism. If your first experience isn’t a bad one and if you understand the system it works very well. The trick is to utilise the latches at each end of the board… use these to push the board into the chassis and, when it nears the bottom, hold them in such a way that they cannot leave the vertical position and snap shut. If this is done the board will drop just a short distance but the clasps will hold the delicate interconnect away from the internal baseplane. Once this has been done it is a case of gently closing the clasps to properly install the system board.
Unfortunately it seems that somebody wasn’t aware of this technique and the cost was our V1280 baseplane. Fortunately we didn’t lose a system board at the same time.
Months went by until last weekend we reworked the lab and moved this system to a rack that has an anti-tilt mechanism (it’s just a foot that sticks out). I immediately ordered a replacement baseplane and got around to installing this yesterday.
The procedure is relatively straightforward, but the twist is that the baseplane is on the bottom of the chassis (logical, but different from the other Serengeti boxes). After removing the power supplies, the main fan tray, the IB_SSC board and a crazy internal power board I was ready to lift out the three system boards and two repeater boards. The proper thing to do here is to lift them up a few inches until they are properly held by the ratchet mechanism. As I’ve already mentioned, this is strong and holds the boards well.
Next up is ten minutes lying on my back undoing the screws on the bottom of the chassis. “Undo 31 of the 32 screws securing the baseplane. Remove the final screw and be prepared to support the weight. WARNING the baseplane is heavy.”
Fortunately all of this went off without a hitch. One thing I particularly liked was the ability to lie with my head under this monstrous box and look up at the five high density interconnects above my head. Each “pin” is so fine that it can (and often do) pierce a hole in the surround of the female high density connector they mate with… certainly not something I’d like to have land on my head!
The good news is that following the baseplane replacement the system is back up and running. I have one issue left regarding the two onboard gigabit ethernet interfaces, but this is a very minor issue by comparison.
Another job well done :)
Tags: Work