A couple months ago I bought a "plug and play" Ethereum Miner off Ebay for $4,000 (I will list the Amazon links to the parts below if you would like to build one yourself.) I plugged it in, and.....nothing. It didn't boot up. WTF?!?! It can be pretty emotional when you drop a months worth of wages on an investment and it doesn't work. That problem ended up just being an unplugged hard drive - and that was just the first of many. As a complete noob going into this, I knew nothing about troubleshooting so I spent many hours on discussion boards and youtube trying to figure it out.
If your rig is freezing and you've messed around with voltages and overclocking, return everything to the stock overclocks and see if it will mine. If it does, slowly increase you overclocks and other adjustments to find a sweet spot.
If you are still having problems with your multi GPU miner, try these steps:
Shut down your rig. Anytime you are adjusting hardware the computer should be off.
Disconnect all of your GPU's from the motherboard except for the master GPU. In my case, this is GPU #2 which is plugged into the second riser card adapter slot. To be honest, I don't know why it's the second one on my rig.
Plug your monitor into the master GPU, not the motherboard.
Power on, start mining. If it starts working fine, let it mine for 30 minutes just to make sure. If it doesn't work, then there is most likely a problem with this GPU and/ or it's connection. Let's assume that this one worked fine.
Close miner and shut down the computer.
Starting on the left, plug in the next GPU.
Power on and start mining, run for 30 min.
Repeat this process, adding a new GPU every time. When you plug a new GPU in and it fails to mine properly, you have isolated a problem!
Ok, so now you know which GPU is giving you problems. Most likely, it's not a bad GPU, but rather bad connecting hardware. Below I will list common problems, starting with the most common.
Bad Riser Card. The riser cards on the market today all seem to be really cheap and it's common for 10%-20% of them to not work properly when new or go bad shortly after. Replace the riser card and the connecting cords that go with it. If this doesn't work, switch it out one more time just to be sure.
Bad Power Cord. Check the power cords from the PSU to the GPU and back. Unplug at each end and do a visual inspection. I've had a bad cord and the housing at the end melted into my PSU. If something like this happened, look for the cord on Ebay.
Driver not installed properly. Make sure you are using a driver that's compatible with mining. In Device Manager Expand "Display Adapters" and "Sound Video and Game Controllers." Make sure all of the GPU's that are plugged in are being recognized and don't have any yellow triangle with exclamation mark icons. If you do, uninstall and re-install your GPU drivers.
Bad GPU. Yep, I had a brand new ASUS RX580 that wouldn't work at all. Talk to the manufacturer or retailer for a refund. Hopefully this isn't the problem.
Let me know in the comments if I missed anything or need to change something. Hope this helps!
Some components:
GPU's - http://amzn.to/2jCM4M9
Motherboard - http://amzn.to/2j8nYcN
RAM: http://amzn.to/2nmLqaQ
Processor: http://amzn.to/2j9kVRw
Power Supply Unit: http://amzn.to/2kfsE45
Hard Drive: http://amzn.to/2jDXwHF
Google Wifi - http://amzn.to/2jCGppi
Toolbox: http://amzn.to/2AmnSrg
