Check the powerpack.
My DSC-HX100V suddenly stopped working earlier this year. Couldn't get it to switch on and couldn't power the battery. Went to the local Sony store who couldn't offer any help. Then went to another local camera store who sent for repair but nothing could be done.
My husband found a website which seemed to offer help, advise and a repair service, but to get it repaired had to have a fully powered battery. So we purchased a separate battery charger via Amazon - and guess what the battery charged and the camera worked!
So then husband goes and buys a new powerpack - and yes the camera is now fully functional with 2 methods to power up the battery.
Just to add insult to injury - I had just purchased a new Sony to replace the 'broken' one
