There are several reason why a printer would stop during a print. The most common has to do with the power supply or the power supply connection on the motherboard. There are several other reasons that can be quite common. The following categories will refer to anything related to your computer, the power supply and connection, USB cable and ports, and motherboard (specifically overheating).

Related to Your Computer

The first thing we would like you to check is to ensure that you do not have your computer set to go to sleep. If the computer goes to sleep, connection will be lost and the printer will not be able to continue where it left off.

Memory intensive programs - while most of the time you will not have an issue with another software interfering with a print, if something causes the computer to use a high percentage of its memory, it can disrupt communication with the printer. Browsing the internet and folders will not likely cause this to happen but just be mindful of how many processes you have your computer doing during prints.

Operating system updates - If your computer is set to automatically install updates to the operating system, it will prioritize these updates over printing. Most of the time, the updates may not even be installed until the computer is turned off so they will not interfere. It is primarily a concern when the updates are installed automatically and they are related to hardware drivers. If the installation automatically restarts your computer, it will interrupt the print and you will need to restart it. Just to be on the safe side, avoid installing any major updates to your computer while a print is in progress.

Power Related

This will be divided in two parts. The first is related to your printers power supply and the connection on the motherboard. The second is related to the power source such as the wall outlet.

I. Power Supply and Connections

The power supply itself could be faulty causing intermittent power that will result in failed prints. Primarily note any visual signs such as the lights of your machine momentarily turning off and back on. Also look at the power supply LED to make sure it is steadily turned on.

More commonly, the issue is with the connector that goes to the motherboard. If it does not fit securely inside the connector, the movement of the printer while printing can be enough to lose power very briefly with no visual signs such as light flickering. One way to troubleshoot this possibility is to use either a zip tie to secure the connector in place. Then attempt the print again. You can also move the connector around while inside to see if any slight movements cause power interruptions that you can see (note: you do not need to do this while printing).

In rarer instances, it is the soldered connection that is at fault but this is harder to diagnose.

II. Power Source

If you have your printer connected to a power strip or a wall outlet that also has other power hungry devices, you may experience problems with printers stopping. The reason is that if there is a sudden spike, it may be enough to interrupt a print. You may want to try having the printer connected to another source as a test. If you have a UPS available, connect the printer there since it will help with the power being more steady.

USB Related

Finally, please check to make sure your USB cable is connected securely to the printer. If the connection is loose, the same thing can happen as with the loose power connection. The movement of the printer will be enough to interrupt communication. You can also try using a different USB printer cable as a test to rule out the cable itself or motherboard connection.

If you are connected to a USB hub, connect directly to a computer port instead. Generally speaking, you will want to avoid using usb hubs if possible. A good quality usb hub will be fine most of the time but go ahead and connect to a port on the computer as a test. You can also try a different port on the computer.

Final Steps

Please go through this and jot down any information from each step. The more you can rule out, the easier it will be for us to assist you in fixing the problem. Just take some time to go through them and let us know what you found with each one. We will be better suited to assist you with this information.

However...
Has anyone with these issues tried looking at some of the other advanced power options? i.e. Hard Disk power down, USB Selective Suspend etc...

On the laptop I use I have "Sleep after", "Allow Hybrid Sleep" and "hibernate after" all set to never for both battery and plugged in option

Also, Under Device Manager - properties of the Com Port that the printer is connected to and the port settings tab there is an advanced button.  Here you can manually change Tx + Rx Transfer sizes, Latency timer and timeouts.

Again not sure if any of these things will work but might be worth taking a look at.

So the question is, what causes this, and how do I fix it? I originally didn't blame the printer because I thought it was the PC, but now I'm just really annoyed. I'm at the point where I've had enough printing experience that I want to do some larger and cooler prints, but can't leave it to run unsupervised as I'm scared it will burn my house down. Also attempting the same print multiple times to get one good one (start to finish) is such a waste of material.