Hp dv6000 laptop beeps 4 times n won't display on start up

Most likely a memory problem. If you have more than one stick of memory, remove one and try it.
If that doesn't work, remove the other one and replace the one you took out.

Your Pavilion DV6000 laptop is the key to your productivity, which is why it is essential that it turns on when you need it. The DV6000 is lighter than comparable models from other brands, and has a large, sharp display. While it has plenty of processing power, the DV6000 can have normal boot problems as well as problems caused by faulty battery packs that were installed in some units. Attempt to troubleshoot the laptop and find out if the laptop is eligible for a new battery pack.

1.Hard reset your laptop if there is no life at all. Unplug all peripheral devices and remove the battery. Unplug the AC cable and press and hold the power button for at least 15 seconds to drain all power. Reconnect the AC cable and hit the power button.
2.Verify that the battery pack is on the recall list if the laptop powers up without it. Fill out the form on the battery pack recall website (http://bpr.hpordercenter.com/hbpr/). You will have to input the serial number of the battery pack as well as a location to ship the replacement battery if you are eligible.
3.Hold the AC cable where it plugs into the laptop and wiggle it while hitting the power button one time. LEDs that come on and off intermittently indicate a faulty power cable. Order a replacement power cable through HP or a third-party vendor.
4.Write down any visual or audio error codes such as LEDs blinking or unusual beeping. The error sequence will be helpful when talking to an HP support person.

I hope this may help your concern.

No Screen on Pavilion DV2000T
I had this problem before. Tere is a good chance this may work.
First of all remove the ram memory.

-remove battery pack and wait 10 mins
-now start charging laptop without battery pack for 2 mins
-unplUg the power AND press and hold the power button for 45 seconds
-REPLUG THE POWER CABLE BUT DONT PUT THE BATTERY PACK YET

NOW OPEN THE LID WIDER YOU CAN PRESS POWER BUTTON YOU WILL SEE YOUR SYSTEM WILL START. ONCE YOUR SYSTEM IS READY SHUT IT DOWN PUT THE RAM AND BATTERY PACK BACK AND CONTINUE TO USE YOUR LAPTOP.

It hope fully will work as if you get one or more beeps, the POST is completing alright.
Hope that helps.

does it display on external monitor, if yes then do not worry just change the balesh of the screen of ur laptop it does not cost more,, for more view www.ecwnepal.com

besides the beeps which indicate a motherboard timing issue. There should be LED blinking codes given on the front LEDs. I will include the blink codes below, but lets try to at least get the system up and running. First, I would like you to remove the RAM sticks from the laptop and just reseat one stick back in the machine. Try to boot with that one stick, if it does not, try the other alone. There have been issues when reseating the ram or re-installing it have temp. fixed the issue. If it does reboot, go to the HP support site, put in your model number of your laptop and download and install an updated BIOS. Below are the blink codes that may narrow down the problem.....

HP DV6000 LED Blink Codes

LED Component Error Condition
Blinking battery power LED Battery Insufficient charge on the battery
Blink: 1 - Caps Lock/Num Lock CPU CPU not functional
Blink: 2 - Caps Lock/Num Lock BIOS BIOS corruption failure
Blink: 3 - Caps Lock/Num Lock Memory Module error not functional
Blink: 4 - Caps Lock/Num Lock Graphics Graphics controller not functional
Blink: 5 - Caps Lock/Num Lock System board General system board failure
Blink: 6 - Caps Lock/Num Lock BIOS BIOS authentication failure

Please check the battery. You might have to replace the battery bcos it definately gone bad already.

If your system board fixed but come trouble again.

Sometimes flex power cable problem too.
Check out internal your system.
or Mainboard problem. video chipset.

try buying a new battery

More info please. Does it show a boot screen first then go blank? Does it beep when you turn it on? Has your display flickered recently or have the colors shifted?