If the MacBook is not lighting a USB mouse after 1 minute of initiating boot and the CPU is cold, it is not posting. If it is lighting this, the issue is no image.
Find out what problem it has, then we can advise. No image and no chime are completely different issues and need to be investigated differently. If it is not passing POST, check out the CPU power rail and SPI ROM area. With board level repairs, it is very difficult to advise with the more complex issues over the Internet without looking at it; thoroughly check over the board using a microscope to see if there is any minor liquid damage or corroded traces