20 Most Recent Sony PS-LX300USB Turntable Questions & Answers

This sounds like the belt, if it is a belt drive model, has slipped to the wrong position on the motor post. You should be able to set it back up right. As long as the belt is not worn out. Any recordings at 45 can be converted to 78 using the software. There should be an option to do this. This applies to all other speed settings too. You can convert 33 to 45 etc using the same thing.

I assume you mean a software disc is missing. Then all you need to do is use this site. It will be in warranty so they should be able to send it out. If you have not registered the device do so at the same time. http://www.sony.co.uk/support/en/spare-parts

You have either knocked the connections to the cartridge causing a loose connection, or not seated the stylus right. Or you have static build up, which can be caused by poor earthing.

I don't exactly what you are referring to by zero weight, but if it has a P Mount type of cartridge, there are no adjustments, such as tonearm balance, stylus pressure or anti-skating. For more information, please visit my website at audioserviceclinic.com. Thank you.