I recently received a second hand Dell all in one PC that refused to boot. After a cursory examination of the motherboard I discovered that nearly all of the capacitors were either greatly swollen or already burst. Without a great deal of solder surgery this system will never boot again. I currently have a re-cap project in the works and the value of the system is such that it is not really worth the work required to replace all the different caps on this board. While I was carrying the corpse to the dumpster a thought struck. Here I have a perfectly functional PC case/monitor combo with no motherboard. On the other hand, I have a perfectly serviceable Raspberry Pi and I have no clue what to do with it. Why not combine the two into a (not very) portable PC monitor combo and break out the Pi’s various inputs and outputs and run them through the various ports on the computer case.
Step 1: I started with a defunct Dell 745 OptiPlex “All in One”
Step 2: I removed the unit from the monitor and completely emptied the case. Motherboard, fans, hard drive, and all other hardware connected with the original system was removed.
Step 3: I used one of the original motherboard risers to mount a Raspberry Pi (running Raspian) in the center of the case. It is currently booting from an 8 GB SD card. I investigated the possibility of actually using the SATA disk drive that came with the original system but discovered that there is no SATA controller available on the Pi and no way to connect one to boot. I will have to continue to boot from the SD card and then mount a USB hard drive for file storage, etc.
This is as far as I have gotten tonight. I have a 7 port powered USB hub that I will remove from its case and wire into a circuit with the existing power switch. I can connect the hub to the existing ports in the back and front of the case to make them operational again. I have also purchased an HDMI to VGA converter that I can attach to the original VGA port on the back of the case and plug the HDMI into the PI. I know I could just use the HDMI straight out of the case and connect to an HDMI monitor but the built-in monitor only has a VGA input so it would violate the build idea of keeping everything as original as possible. Instead of a built-in power supply, this case uses an adapter transformer similar to a laptop charger cable. It uses an eight port plug to connect to the case. I can build a Molex connector and break out the power to run the Pi, the USB hub, and any other components we may need. I can also run a network cable from the Pi to the wired network connection port on the back of the case to make it operational. Now I need to figure out how to get a “breakout” cable to allow the various input/output ports on the Pi to be used without opening the case. As the build progresses I will update the blog. Meanwhile, school starts back up on Monday and our robotics contest is Jan. 24th. Wish us luck.