I hit the power switch on my laptop and the screen stays blank but the scroll lock and caps lock blink every 3 seconds

You may have memory problems. Memory module(s) may be defective or not seated correctly in place. Check the memory modules first. It seems that you have already checked the RAM modules.
Connect the computer to a monitor and reboot to see if anything is displayed on external monitor.

well one thing eles my scooder i just got it

That is a security configuration on HP Laptops, depending on the way they blink is the problem your machine has.

Here is the web page where this info is posted, in case you need more info, hope this helps you to determain.

http://h10025.www1.hp.com/ewfrf/wc/document?docname=c01443366&lc=en&dlc=en&cc=uk&lang=en&rule=26781&product=3816592
This document pertains to HP Notebook PCs with the HP Unified Extensible Firmware Interface (UEFI) beginning in late-2008. On startup, you may see a blank screen. If the diagnostic utilities detect a specific problem with hardware components, the fan turns on, but the screen remains blank. To help identify the cause of the problem, various LED lights on the keyboard blink a series of codes. The diagnostic utilities use the LEDs near the Num Lock or Caps Lock keys to blink a series of error codes. At the end of the series the blinking stops. The pattern of blinks will occur any time you attempt to start the computer until the error is resolved. Battery power LED blinks The Battery power LED indicates the condition of the power supply. When starting the computer, or when the computer is in operation, use the chart to identify the power condition. Battery Power LED Component Tested Error Condition Battery power LED off, and Caps Lock/Num Lock off Battery or AC Adapter AC adapter not connected or failure

Battery low charge or failure Battery power LED blinking Battery Insufficient charge on the battery When new computer is used for first time, the white LED light for the AC power connector blinks. Battery is still in "Shipping Mode", the light continues to blink even when AC power is connected.

To resolve, turn off notebook, connect AC power and allow battery to charge for at least 30 minutes, then start computer. LEDs near Caps Lock and Number Lock keys blink when starting notebook The LED lights near the Caps Lock and Num Lock keys will blink if an error is detected during the start up process. The LEDs will blink a number of times in a sequence and then stop. The number of blinks in the sequence indicates what component caused an error when it was being tested during start up. If the LEDs stop blinking and the computer does not start, you can press the power button again to repeat the tests. Count the number of blinks, and use the chart to identify the error condition. Knowing the number of blinks is helpful when you contact an HP support agent for technical help. Caps Lock/Num Lock LED Component Tested Error Condition LEDs blink 1 time CPU CPU not functional LEDs blink 2 times BIOS BIOS corruption failure LEDs blink 3 times Memory Module error not functional LEDs blink 4 times Graphics Graphics controller not functional LEDs blink 5 times System board General system board failure LEDs blink 6 times BIOS BIOS authentication failure

How many blinks between pauses if there are pauses? Look at this chart.
Number of Blinks or Beeps Location of Blinking LEDs Component Being Checked Error Condition Continuous glow Battery power LED Battery The AC adapter is attached and the battery is charging, but does not yet have sufficient charge to power the notebook. 1 Caps Lock/Num Lock CPU CPU not functional 2 Caps Lock/Num Lock BIOS BIOS corruption failure 3 Caps Lock/Num Lock Memory Module error not functional 4 Caps Lock/Num Lock Graphics Graphics controller not functional 5 Caps Lock/Num Lock System board General system board failure 6 Caps Lock/Num Lock BIOS BIOS authentication failure Continuous blink AC power adapter LED Power adapter Insufficient power

This is usually indicative of an internal malfunction. You can try unplugging it from power, removing the battery and holding down the power button for 30 seconds with everything removed (to discharge any capacitors on the motherboard.) Then plug everything back in and try to fire it up. If it still doesn't work, there's a good chance the unit will need service. Local repair shops can usually be found on google maps or craigslist

Hello good day,sir
My compaq presario cq40..is powering on but blank on the screen and caps lock and num lock blingking only.I try ready so many time but everything are not meaning for me that's why i need your help,sir.please,give me some advice for power back.
Thank sir.

You need to launch the Last know good configuration to get this fixed.

Follow the steps below,

Step 1: Shut down your PC completely.
Step 2: Turn on the Power button.
Step 3: As soon as you turn it on start hitting the F8 key on your keyboard until you get to a black screen called "Windows Advanced option". (If you don't get to that that screen but you end up reaching the blue screen than that means you have delayed in hitting the F8 key. start again from step 1.)
Step 4: As soon as you reach "Windows Advanced option" use your down arrow keys to choose an option called "Last know good configuration".
Step 5: Select that and HIT ENTER.
Step 6: you PC will boot to the windows. If this fails then you need to perform repair install using the Operating system CD.

just remove the ram and clean it and fix it again or you can try with connecting other monitor and make sure the laptop is booting properly only problem with screen.

click here to find the details.

you may also like to click here

that wouldn't mean the processor is off, it means there is a problem with the motherboard. I don't know the exact problem with the motherboard. but it could be something wrong with the processor too. but I suggest you take your PC to like Circuit city, best buy, or your local computer shop to have them take a look at.