Sony Tablet Fas Not the Master Resset.

Personnel need help. I live in Brazil and I have a tablet model Sony SGPT112US / S. When I call him, he is only the Sony logo. When I try to do the master reset does not work. Is there any other way to reistalar the OS it? I've been in several assists and they just tell me that you need to replace the motherboard, only that it will cost $ 300.00 dollars. Does anyone know of any other way to reinstall android it via usb cable? I thank the attention.