This Old Server, Part 2: Drilling, Grinding and WiringPosted: October 19, 2013
Continuing from my last post, I have a “new” Dell 1800 server case, but I needed to adapt it to a white-box motherboard. I had originally planned to buy the new motherboard after getting the case, but delays and SATV work compelled me to get the new motherboard running in the old, junky case while working on the Dell case. This is my new Supermicro H8SCM-F server board, which is considerably smaller than the original Dell board.
I forgot to take photos of the grinding and drilling I had to do to this point, so I’ll have to describe it. I used a cutoff wheel (and safety goggles!) to grind off the original I/O plate, and several of the standoffs. I then drilled new holes, marking them off with my old Tyan motherboard as a template. This was a lot of fun, well, not so much. This was, after all, a “real” server case, so the steel baseplate is thicker than one sees on a white-box server case, particularly the cheap ones I have encountered.
Most white-box cases have a frame in the rear to hold the I/O plate. The Dell doesn’t, as the I/O plate is part of the motherboard tray. After much cursing, I used aluminum tape to secure the I/O plate, and I did get the tray and the board to fit inside the case securely. I’ll need to rip off the tape if I change the motherboard. That’s acceptable.
On to the front panel.
There are three buttons on the board for POWER, ID and NMI, plus a socket which connects to an intrusion switch mounted on the lower front of the case. There are two LEDs, one is a bicolor blue/orange that is used for power on and alert indications, respectively, and a blue LED that blinks when the ID button is pressed. There is also an LM75 thermal sensor on the board. Here’s the pinout as best as I could trace it, for posterity’s sake. LED1 is the bicolor power/alert LED. Blank pins are either not used, or I could not determine their function.
|2||GND, LED 1 pin 2|
|3||NMI switch positive|
|5||ID switch positive, LED 1 pin 3|
|6||NMI switch negative|
|8||Intrusion switch, pin 3|
|9||Power switch positive|
|10||I2C clock, SN75|
|12||I2C data, SN75|
|13||Intrusion switch, pin 2|
This is proprietary to Dell, and was not a match for my Supermicro. It wasn’t feasible to modify the front panel for my motherboard, so I just cut an Adafruit breadboard down to the size of the original.
More about the front panel, and finishing my server, in my next post.