1) Make sure the PSU will turn on without being plugged into anything with the "paperclip test"
http://www.youtube.com/watch?v=khpnx21oydgIf it does not power on then you have a bad (or 2 bad) PSU and need a replacement, I recommend at least 750 watt preferably 1000W+
2) If PSU does power on, then make sure you are connecting the power cables correctly:
![](https://ip.bitcointalk.org/?u=https%3A%2F%2Fen.bitcoin.it%2Fw%2Fimages%2Fen%2Fc%2Fc1%2FAvalon-pdu-v1.2.JPG&t=665&c=PVpxv5Z9kwskCg)
Note: some of the internal cables and connectors could come loose during shipping. Not likely but possible, they should be checked to make sure a flush and tight connection is made - make sure everything is plugged all the way in.
The far left 6-pin port connects via a short cable to the controller board. Don't mess with it. Next to it is the ATX_24p connector. It has 24 pins and it connects to the big 24 pin connector (some PSU have 20 + 4 that need to be pinched together during plug in, this can cause a problem if the 20 pin clicks in but the +4 pin is not completely plugged in). Make sure the PSU 24 pin is plugged in correctly, with the depressable tab on "top" facing to the right where it matches up with the tab catcher on "top". It should click when it is all the way plugged in. It is a tight fit and hard to get this plug in without hurting your fingers or using needlenose pliers, put do what you must to get it in.
All the 4 connectors in the middle are for internal cables that power the ASIC cards, they should already be connected. Don't mess with them.
Another difficult plug is the 8-pin EPS_12V on the top right. That is for the 8 pin motherboard power cable on your PSU. Some PSU have a 4+4 that you have to squeeze together to plug in. Either way, make sure it is plugged in fully and in the correct direction with depressor tab matching catching tab. This will make it "backwards" relative to the 24-pin cable, with the "top" of each connector facing each other. Go figure.
The easy and obvious two plugs are the PCIE_12V_1 and PCIE_12V_2. These connect to the PCIE connectors, obviously, with some PSU having 8-pin and others having 6+2 pin. Once again if squeezing together, make sure both parts are tight and flush, plug all the way in.
So you should have plugged in 24-pin, 8-pin CPU, and two 8-pin PCIE power cables, then see if it turns on.
3) At this point it should give you a red light for something wrong or a blue light for things going OK. Let us know if you continue to have problems.