Hey all, wanted to share the work I did on a Quad G5 I picked up earlier this year. Had a short obsession with owning the last generation of various PowerPC Macs. Found this Quad on ebay, no description and hardly any pictures. Asked the seller for a shot of the serial # label and found that it was a Quad! I took a risk and bought it for around $100 It arrived in great condition. The case is in great shape, no bends, light cosmetic dings. stock 7800GT fan was noisy but it worked, came with a HD too! Come to find what others have in the past, the LCS needed a rebuild. Overtemp and checkstops, LOUD fans. This was my first watercooling venture, so shopping around for parts took some research to find what I needed. Using this guide I rebuilt the LCS using Tygon tubing, XSPC Clear fluid, DIYINHK DDC Pump PCB, New O-rings, and anti-kink coils. My unit originally had the dual pump system that was epoxied to hell. Deemed by me impossible to rebuild. So, I bought a LCS off ebay, single pump system and did a refurb. I did also buy a Panasonic unit too just for fun, but came to find that it doesn't fit at all. Hanging onto it for a future watercooling project. This LCS Loop went through about 4 revisions. Had to drain it about 6 times. Went through 3 different pumps because they were stuck max RPM. Finally replaced the PCB. Had to move the T-line reservoir to the intake side of the pump, added a kill coil, and adjusted tubing lengths a few times. I'm content now but I got seriously tired of taking this in and out of the G5. The pumps kept getting stuck on max RPM. Not sure what it is about taking this system apart but it managed to happen a few times. I had it wired up to the onboard connector but it had a really loud whine at full speed and wouldn't throttle down at all. Also, at full speed the pump was doing its share in heating the coolant, thus, raising core temps. My solution to the pump problem was to use a fan/pump controller. Regular cheap fan controllers don't have enough power to supply the pump with consistent voltage. I used the mCubed miniNG controller. This thing is really awesome. Gives enough startup voltage, has a sensor to make sure the rotor always spins (blockage recognition), choose between PWM or voltage based control. I chose voltage based and set it at one speed. Only catch, it doesn't communicate with the G5. Though I've found that on the lowest RPM it cools just fine. As long as coolant is flowing the core temps are around 35-40C idle. Unfortunately, there isn't a readout for changes made to the controller, speeds are adjusted with a potentiometer. Perfectly acceptable, and this pump is now inaudible and thermal calibration passed. Had issues with the thermal cal a bit ago. was throwing an "intake fan speed error" which I found there was a bent pin on CPU socket A. Put that back in place and boom, passed. Configured with a flashed 7800GTX openmark score 18867 added more RAM 10.5.8 using tricked versions of Dropbox and Skype. Even an older version of Photoshop too! This thing's great and hums along!