(1) Restart the computer. Immediately after the chime hold down the (Command-Option-R) keys until a globe appears. (2) The Utility Menu will appear in from 5-20 minutes. Be patient. (3) Select Disk Utility and click on the Continue button. (4) When Disk Utility loads select the drive (usually, the out-dented entry) from the side list. (5) Click on the Erase tab in Disk Utility's main window. A panel will drop down. (6) Set the partition scheme to GUID. (7) Set the Format type to APFS (SSDs only) or Mac OS Extended (Journaled.) (8) Click on the Apply button, then click on the Done button when it activates. (9) Quit Disk Utility and return to the Utility Menu. (10) Select Reinstall OS X and click on the Continue button.
Go to the BIOS and check it , it is sharing the memory with the VGA even though it is showing dedicated VGA but if you reduce the VGA Memory it will have some performance issue like when playing games, or 3D applications
it looks like the Screen inverter has gone defective you will have to replace it, The display inverter is the circuit which gives the power to the screen backlight. connect to an external monitor and check if the display is coming, if it is coming then you will have to find an inverter online and replace it. you can buy the part from here: LINK i would suggest replacing the laptop since it is outdated, if the circuits starting to fail most probably other issues will come in the future
if you have a spare laptop same model which has a battery backup power try using that and check, or drain the battery completely and keep it for a full charge for 4 or 8 hours and check If not you will have to replace the battery. better
(1) on the network, icon check if you can see the Wifi Icon,, if yes click on that and see if you can see the wifi name that can be connected IF NOT GO TO STEP 2 (2) check if the wifi connects to the mobile hotspot wifi, try connecting to other wifi, if connecting, then check wifi router mac filters and see any mac address is blocked in that if you cant do the above go to Control Panel >> System >> Device manager >>in the network adapter check if any wireless adapter is installed, if not check other devices ( Unkown Device ) right click and try to install the drivers, IF THE DRIVERS IS INSTALLED REMOVE AND REINSTALL AGAIN DOWNLOAD FROM THE SITE download the drivers from link
if no power try replacing the power cable, if it is error B203 try the below link steps, Sometimes, the Error Code B203 indicates that there is an empty ink cartridge. Now, if your Canon printer is running on two different kinds of ink cartridges. Then, it might possible that one of them is empty and that is creating this error on your system. LINK or tey doing a hard reset : LINK