Computer takes a long time to turn on...

Is that 30 minutes of waiting or constant wire plugging and unplugging.

The question was a one or the other, not yes or no.

It sounds like a bad cable or connection, nothing else to me would make this happen. When you finally get a good boot have you updated and run your Anti Virus and done deep scans? Do that and then restart into safe mode and run the updated virus in a deep scan in safe mode.

Start it and run scans also if you don't have Malware Bytes please down load it (free version) and run it. If anything comes up keep running them till clean. quarantined.

Hello Raiden92:
From what you have posted in this thread and the videos on youtube it sounds like this machine only boots once in a while. Hardware issues and even Bios issues can be a PITA to figure out but steps must be taken in an orderly fashion and protection from static must be adhered to. If you don't already own one I would suggest an antistatic wrist strap. It is a cheap insurance against permanent damage to your components. Newegg.com - antistatic

Usually with a machine that will eventually boot there are two things that come to mind that I have had experiences with. 1) Memory 2) Memory. First try one stick of memory, then the other. I would suggest clearing the bios after each attempt. (With the system completely unplugged and wrist strap in place pull the bios battery for 30 seconds while holding in the power button) If you able to eventually boot into your bios I would suggest loading defaults and rebooting.

You have tried a different monitor with a separate vga cable so I doubt there is any future in going that root.

You can unplug the data and power leads from hard drives, dvd drives, unplug the front panel card reader (note which port it plugs into). and see if this beast boots to a os not found screen then we plug in the dvd drive, if it boots quickly to os not found, then plug in hard drive ect. each time rebooting. This will weed out any culprit hardware.

First and foremost be prepared to learn a lot about your hardware and have patients. when you find the moment it stops booting good you may indeed find the issue at hand. Also I would take a flashlight and inspect the Capacitors on the Motherboard. look for any bulging, leakage, swelling. Leaking and Swollen Capacitors on Motherboards and Power Boards - YouTube if any look like these be prepared to replace the motherboard or get real good at soldering real fast.

I have added my twenty cents (inflation don't you know) and hopefully you can find some help there. If you don't understand a step just ask and I am sure someone here if not myself will be able to explain.

Good luck and have a good day.