Bought 15R3 for a year and a half. After installed the latest BIOS 1.6.0,  the system started to get very unstable and got BSOD from 1 time a day to serveral times a day. However sometimes it will stay okay for a few hours.

The BSOD have a few errors, but usually are:
"critical process died" and "unexpected store exception" and sometimes other codes which i didnt marked down.
And when it reboot itself it will pop up a window saying  "Boot failure on device". Also after installed the latest BIOs, when powering on it ll pop up the "checking media presence" and ipv4 and ipv6 before booting to window. I tried to downgrade back to 1.5.0 but this would stop the BSOD popping up. 

I did all the tests and diagnoses suggested from dell and other websites:- dell full diagnose test, sfc scan, running troubleshoot etc. but all saying no error found. Also performed some checking on the SSD and HDD to check if theres any bad sectors, also are fine.

Then I had done 2 window resets. 1) with the files remaining and 2) clean boot. After first reset BSOD still happens so I decided to perform a clean reboot.  I can still turn on my laptop but BSOD still happens from time to time, just that not so often.

I have looked at other post here suggesting there might be problem on the toshiba SSD. Would changing the SSD solve the problem? Any other suggestions would solve the issues?

P.S. Warranty has expired for half a year. Would extend/renew my warranty and send to dell able to solve my problem without paying a vast amount of money? (Have called the technical hotline, the guy suggested that might be a motherboard problem and replacing motherboard would cost like 1500USD)