(H8) Day5 Hardware Basics part8 Issue at Boot time, Black screen, Bootable device not Found

20240607 120107
Boot Processing:
Step by step process of -When power on the System/PC to User’s working Screen
POST -Power On Self Test
-system tests itself all components (main - CPU,MB, RAM,BIOS….) working or not
-POST Success next step
- 1 beep sound or no beep
- Keyboard - led blink once
- Power LED and HDD LED Blink
- On Monitor something -like bios, PC logo’s, OS loading,error - shows
-POST Fail - troubleshoot
- no beep , multiple beep , continues , long / shot beeps- based on BIOS manufactures & MB
- No display -blank/black screen, Nothing on Monitor , NO HDD led blink, KB - led no blink,
- Use POST Card to get to understand what is the ISSUE/ Error
- Any of component(main) is failed , not connected , improper connection, incompatible
- most of the cases RAM loose ,RAM slots dust, RAM failures , not properly connected
- CPU
- MB - chips sets, power distribution
- Disconnect all power connections - clean RAM connection, remove and reinsert , cross verify
2. POST Success-check Boot priority in BIOS locate OS device
- ex. OS in HDD - Locate MBR Record
MBR record tell - no. of partition ,Sizes, type, primary, OS partitions,
bootloader location
- on screen “Boot Device not Found” or “bootmgr missing”
-HDD is not working /failed, not connected, no OS in HDD, OS is corrupted, OS Bootable file corrupted
-BIOS setting - check HDD available - yes - OS in hdd issue
-no - check hdd connected, cross verify - replace HDD
HDD NOT WORKING
-if you have System Image Backup - you can restore into HDD/New HDD
-otherwise - Reinstall OS again
bootmgr corrupted
-OS issue - connect OS’s install disk - DVD/Pendrive(or repairdisk) -repair options - win 7 - copy bootmgr file from installdisk/repair disk to C:drive
- win10 - Troubleshoot - Advanced options - startup repair
HDD working - OS related
Startup Repair
Reset this PC
System Image Backup/Restore
Reinstall OS
HDD not working - Add new HDD
System Image Backup - Restore
Install OS
3. Locate MBR record - Bootloader - Load Bootloader into RAM
-Bootloader
- Windows vista,7,8,8.1,10 - bootmgr
-Win XP, 2000,2003 - NTLDR
- Linux - LILO, GRUB-GRUB2
-bootloader tell location of OS and How to load OS
-unable to find bootloader, bootmgr missing - as 2nd step
4. Load OS
5. User will login screen, Login- Startups,Services, applications…
-----------------------------------------------------------------------------------------------
Blank/Black screen- nothing on screen not even an error, no beep sound or continues beep sounds, no keyboard led blink, power led blink, no hdd led blink.,
-POST failed,
-In Generally check RAM connectivity, dust, RAM working or not
- use POST Cards or On Motherboard BIOS LED Status to know which component issue it is -CPU, DRAM, VGA, BOOT
Boot Device Not Found, No bootable device, No boot disk, Operating System not found, Bootmgr missing
-In generally OS is in HDD/SSD
- Check the HDD/SSD working or not
- HDD is not working, replace HDD, restore System Image Backup(if available) or install OS
- HDD is working means OS related issues, OS is corrupted or Bootable files (ex. Bootmgr ) corrupted.
- Use Repair disk or installation disk to boot the system and goto repair options.
Troubleshoot - Advanced Options - Startup Repair
Or Reset this PC -Keep files
Or Restore System image Backup (if Available)
Or Reinstall OS
-----------------------------------------------------------------------------------------------------