turning on n off and no display neither on external monitor

will, this series has an easy with the GPU failing. Sometimes a reball can fix it, other times you may need a new logic board. Here is my answer to a similar question :"

This is a well documented prob with this series of notebooks and if you do a search on the Internet you'll find lots and lots of unhappy and frustrated people. The problem is the motherboard, and the symptoms include loss of bootup, VERY slow bootup, WiFi stops working, etc. is simply that the MOBO board overheats and fries the video driver chip. The cooling design of this PC is inadequate.

You might try this to verify.

1. Take the battery out and unplug the charger

2. With the computer lights OFF, press and hold down the power button for 15 seconds

3. Plug the charger back in and start-up the computer

to fix the problem you will have to reflow the graphics chip.Here are the instructions (VERY LONG AND WORDY)for reflowing the Video Chip

First Step Is Complete Disassembly Of All Parts And Components..

Remove RAM, Remove CPU, Of Course Remove Heatsink and Fan assembly.

Next Step is Insulating the Motherboard... You need to Protect The CPU area, The RAM area, Cover any plastic Plug ports.

Try to leave 1/4 inch area around the edge of the chip free of insulation.

To Insulate the Board.. I use thick pieces of Tin/Aluminum, you can fold up some aluminum foil (tin foil) About 4 folds thickness....

Now that you have your Motherboard Insulated... Make Sure There's Nothing flammable Or burnable Below the Motherboard... it will get quite hot underneath.

You will need a Heat Gun.. You can get one of these at your Local Home Improvement Store, they cost about $15 - $30.. You Will Use ONLY the LOW Heat Setting... I REPEAT..... USE ONLY THE LOW HEAT SETTING ....

Next You Will Need Some Coins.. Yes Coins..

8 Quarters and 2 Nickels... Put the 2 Nickels On the Bottom and Stack Quarters On Top...

Place The Stack Of 2 Nickels And 8 Quarters On Top Of The Graphics Chip...

The Reason for using the Coins: Using the coins serves a few purposes...

1) It Helps Transfers the heat Into The Chip More Evenly/Slowly

2) It Helps Hold The Heat Longer/Then Helps To Cool Slower

3) It Gives The Correct Amount Of Weight That Is Needed To Press The Chip

A Thing To Look Out For...

Hewlett Packard is nutorious for using the RED epoxy around the edge of the Graphics chip.. this epoxy is used to help secure the chip to the motherboard...

This is a process that is Hand Done at the Factory.. And Some Boards Will Have Only A Little Amount of this, Some Will Have Alot of it...And Some are Only Done On The Corner Edges....

If There Is Alot of This On Your Chip, You Might End Up Needing To Carefully (REAL CAREFULLY) Remove as much of this epoxy as able to....You can use a Razor Blade To Lightly Scrape This Off... DO NOT MISS AND SCRATCH THE MOTHERBOARD!!! Go SLOW...

Now Comes The Heating Of The Chip...

Start With The Heat Gun About 6 Inches Away From The Top Of The Quarter Stack..You want to be holding the gun at a 45% angle.. Aim the heat at the Edge of the chip, You Will Start Rotating Around the Chip- around the outer edge of the chip...then use tighter circles concentrating on the quarter stack, then after about 30-40 seconds, slowly move closer to the chip...

Never Move the Heat Gun Closer than the Top Of Your Coin Stack...Then Pull It Back And Slowly Repeat.. The Chip Needs To Get Hot Enough To Re-Melt The Solder Balls On The Underside Of The Graphics Chip Back Down To The Contact Pads On the Motherboard.. and this takes Quite Alot of heating to Do.... You Must Not OVERHEAT the CHip... It Is Best To Underheat it and have to Redo.. than to overheat.. It will cause the solder to break down and even crack/split.. causing failure forever...

This process will take about 3 minutes total.. Once you shut off the Heat Gun.. Leave The Stack of Coins On The Chip And Let Sit For Another 5 minutes..

Now Remove The Coins(carefull they might still be hot)

Remove All Insulation.. Reinstall RAM, CPU, Heatsink and FAN Assembly (and Of Course Thermal Pads or Paste.. Note:. If Paste Is Used.. It Must Be Silver Paste...

Now You Can Connect The Power Button Strip/ Video Cable And The DC Jack Cable.... And Plug In AC adapter .. You're Now Ready To Test For Solid Power and Video....

I hope this works for you cause there are literally hundreds of HP customers out there with the some issues. Hope this helps, good luck.