With the early units, many gamers experienced skipping full-motion video or physical "ticking" noises coming from their PlayStations. The problem appears to have come from poorly placed vents leading to overheating in some environments the plastic moldings inside the console would warp very slightly and create knock-on effects with the laser assembly. The solution was to ensure the console was sat on a surface which dissipated heat efficiently in a well vented area, or raise the unit up slightly by propping something at its edges. A common fix for already affected consoles was to turn the PlayStation sideways or upside-down (thereby using gravity to cancel the effects of the warped interior) although some gamers smacked the lid of the PlayStation to make a game load or work.
Earliest series had potentiometers on the board for adjusting the reading mechanism, named BIAS, GAIN and an unknown one. By connecting a voltmeter between the upper-most metering point near the BIAS potentiometer and the chassis, the resulting voltage could be read. The supposed right values are 1.70 V when a CD is spinning at 1x speed and 1.85 V when a CD is spinning at 2x speed. Further tuning was also possible on the unique potentiometer present on the CD drive. Later series featured an automatic laser calibration mechanism.