I have a monitor(with a credit card reader if that matters) hooked up to a computer. It's been working for a while until it suddenly shut off. I checked the monitor on another computer and it turned on immediately. I grabbed a spare monitor(without a credit card reader) I have and connected it to the "broken" computer and that monitor turned on fine. Is there a specific area I should troubleshoot to fix this problem? When the monitor with the credit card reader is connected to the broken computer, the light turns green.