i have an old SMPS power supply from an old external SCSi drive that died. its outputs are +5, +12V both at 2A. i am powering an old laptop off the 12V output. laptop takes apr0x 1.5A. it runns but i have noteced only when the laptop is on every 15-25 SEC, the humm of the PSU chnges. it gets slichtly louder for aprox 1 sec. is this going to cause problems for me? whay would it doo this is a capacitor discharging and this is more load to charge it back up?