No Display problem

one of the main things to do when our laptop does not have a Display or There is no graphic display on the screen while it has a power indicator, the following can be done.

1. Let’s use an External Monitor that will be plugged into our laptop via VGA or HDMI and power on the laptop. if no picture is displayed on the laptop’s builtin monitor, we can say that our laptop has no display.

2. so we can verify that it does not have a Display let’s put a usb keyboard and press NUMLOCK if it is off and on. here we can see the indication that he does not have a display.

If Laptop is Powering On, but blank screen/Black screen is seen on the display, we may consider the following scenario happening on the laptop.

1. Missing Voltages at VRM section
   2. Missing VRON signal coming from SIO.
   3. Missing VDDQ or RAM Voltages, 5VSus,3vSus.
   4. Sodimm is Faulty
   5. Processor is Faulty
   6. Disconnection on Ball Grid arrray, (PCH, CPU,GPU, Onboard RAM, Onboard Vram or Embedded Graphics Ram Chip, SOC in latest Generations.)
   7. Missing PLTRST (Platform Reset) signal , this signal can be check on the Pin no. 22 of WiFI slot in older Generations
   Pin no. 44 in newer generation of motherboard, If PLTRST not coming then check PCH_PWROK signal coming from SIO to PCH.
   8. Check 33Mhz Clock if coming at SIO
   9. Check 25Mhz Clock if it has glitch
   10. Check Frame Signal is coming properly at SIO
   11. check CS(Chip select) signal at Pin 1 of the BiOs if # or Active low signal. then possibility that there is fault inside your PCH that you have
   To check, Replace , Reball or Reflow.
   12. Faulty Bios

The above scenario has 90% chances happens in your laptop.