Can 5vsb ruin a motherboard if its running at 5.5-5.9 volts?

I got an e-machine from a friend with a bad motherboard it wouldn't turn on at all so I bought a power supply tester (I needed it anyway since I work on computers all the time) but it said the 5vsb was high and it gave me the warning alarm it read 5.9 volts and slowly went down to 5.5 volts so I was just wondering if anyone knows if that could have caused the motherboard to go bad.