If the battery was the main reason i dont believe the computer eould have booted up normally and get to the desktop ilding stage
If nothing else is wrong but a dead battery, a computer will still boot up with no problems. All the battery does is provide a "holding voltage" on the CMOS module so it can stay powered and hold its data. And its data is the custom BIOS settings like the date and time, or boot device order the user sets in the BIOS Setup Menu.
Having a bad battery just means the BIOS starts from a reset - the motherboard's default out-of-the-box status each time you boot.
But, since this is a "brand new computer" - an important fact that would have been good to know in your opening post - this problem should have been called in to tech support for "warranty" repair, and that would have been suggested in my first post.
If this tech guy is the guy you bought this computer from, then he's ripping you off! He should fix it for free. Wires mismatched? That sounds fishy to me and in any case should be handled under warranty - unless you pulled the cables yourself and did not reconnect them to the proper motherboard connections (assuming that's what he means by "mismatched"). Did you pull and reconnect any power cables?
And you don't set anything in the BIOS for monitors! So that sounds fishy too because the BIOS does not care or communicate with monitors. The BIOS communicates with the graphics solution which is a graphics card, or integrated graphics, as in your case. The BIOS can be set to configure which graphics solution is used first (if you have more than one installed) - but it is very rare for this needing to be manually set, especially when using the integrated solution. In fact, if the BIOS is reset, it would automatically go to the integrated solution first anyway.
If this tech guy did not build the computer (and therefore is not responsible for the warranty service), then $40 to sort this out may be a good price. But his description of mismatched wires and monitor settings in the BIOS sounds like he's just making up stuff to justify his time.
If you get more checksum errors when you get the computer back (and I suspect you will), you need to contact the computer's warranty support. It could be bad RAM, or a bad motherboard.
You could be right that the ports from the mobo are bad, in which case i'll need a dedicated video card.
NO! If the ports on the motherboard are bad, the computer assembler needs to provide you warranty support and get you a "FREE" replacement motherboard from Gigabyte!