Sony z3 compact sudden death[ turns on only until the xperia logo then turns off] with 75% battery

[Mehhnta12334]

HELPPP !!! been using my sony z3 compact for years and now its going nuts. It started randomly it suddenly turned off but when i charged it, the phone turned on again then it was okay for a few days then it happened again but it did not recover. Did all the things like pressing the yellow button or factory reseting the device or using the sony companion! still it would not turn on... When i plug it in the charger it turns onn then off and sometimes it shows the charging logo but it turns off, . My warranty has expired because this has been a relaiable phone for me... any help ?? i bought it to our local repair technician, i think he used a flashtool but to no avail ... the  technician adviced me to buy a new battery but is it worth it ? really need help !

[ak301719]

I've had a Z3C for almost exactly 3x years now, it's been faultless and never let me down and still runs as fast as the day I got it but over the past week it's gone downhill quickly and has displayed a lot of the same symptoms as yours and is now on my desk unable to even start.

It's a shame because it's been such a great phone