Summary: A 2-month-old computer is unable to boot. It always restarts following the “MAIN BIOS CHECKSUM ERROR!” after copying over the Backup BIOS. There were some signs of hardware issues earlier (see below). I’ve followed the advice on previous related threads (as detailed below), and fear the motherboard may be defective. I’d appreciate any advice on what else I should try to diagnose and fix the issue.
The computer was built late December 2011 with the GA-Z68X-UD3H-B3 motherboard and hasn’t been modified (or even opened) before the current issue. Two sudden shutdowns occurred near the end of January (roughly 1 month ago). This prompted me to run memtest to check if bad memory sticks or bays were responsible. A single full pass completed successfully. Additionally, the CPU temperatures were being regularly monitored since the machine was built and no overheating issues were observed.
Additional signs of trouble were seen one week ago when the machine had trouble powering up. It didn’t power up the first time, but instead shutdown and restarted seconds later. It then successfully booted. With these troubles I began researching potential hardware issues, but didn’t take any actions.
Yesterday began the insurmountable issues. First, the machine wouldn’t power up to the BIOS flash screen at all. I stripped out all of the non-essential hardware (video card, WLAN card, optical drive, and all but 1 stick of RAM). The machine would now turn on, and after several failed boot cycles it did eventually boot into the OS. In some of these failed cycles the machine wouldn’t even reach the BIOS flash screen. In at least one other, the “MAIN BIOS CHECKSUM ERROR!” message was shown and the backup BIOS was copied over.
From this point, peripheral hardware was added back on; one component at a time. I’d believed the issue was now isolated as a single stick of RAM, which when included would prevent booting to the BIOS flash screen. The system successfully booted to the OS with all peripheral hardware except this single stick of RAM.
The system was then restarted from the OS, and again failed to boot. It would only reach the “MAIN BIOS CHECKSUM ERROR!” and it would encounter this error on every boot. Again, all of the peripheral components were stripped out, but the machine still encountered the same errors.
Several solutions proposed on this forum for similar situations were tried: The motherboard battery was replaced, the machine was left unpowered without the battery overnight, and the latest non-beta BIOS was flashed onto the motherboard using Q-flash. Lastly, I just allowed the machine to go through the failed boot cycle six times, as some people had mentioned the motherboard might be able to break out of this loop eventually. Nothing has fixed or even changed the current issue. At this point I’m not sure what else can be done.
Is there anything else that I can try to diagnose and fix this problem? Is it possible there is a true hardware-level issue with the motherboard, and this cannot be fixed? If so, why didn’t it present itself immediately? Would such a defective motherboard fall under the standard warranty?
Thanks in advance for all and any help!
