repairing toshiba laptop satellite L355-S7835 model no. PSLD8U-01F00Y,, Im michael the problem is continously shutting down and restarts. When i turn it on,pass the BIOS,and when the windows loading or the windows sign appear the bluescreen appear in less than 3 seconds,it shutdown and restart again and again. But when i go to BIOS clicking F2 it doesnt shutdown even if standby it for hour,before it happen a warning comes out that ì have to change my hard disk,i didnt know what i remove then the word "bootmngr is missing".hope for your answere thank you and GOD BLESS