I have an older Hitachi HT-50S direct drive turntable. For the first time today, the turntable sped up from its locked 33RPM on two occasions. I say locked because there is a little light that lights up when the platter is at the right speed. When the platter sped up, the light turned off and the playing record would sound weird (higher pitch) for a few seconds before going back to normal. It's written Quartz Unitorque if it can be of further info.
My dad said that maybe it's because of the power line feeding the house, or another device that pulls the current when switched on.
Could this be a possible cause? I would expect the turntable to have some kind of system that would regulate the power for such events since it directly affects the sound (if this is the case).
If not, what would be some troubleshooting that could determine the cause? Or even a simple fix if the cause is known?
Thanks ahead for any help!