Friday, January 13, 2012

DV4-1255dx - No Video, Blinking lights on topside

Needle in a digital haystack - numerous problems

Damaged Coil Side view

Problem described as Memory Slot Not working & No Video

Since I had never seen this unit come on, with memory in slot 1 or slot 2 there was not much I could do other than thoroughly inspect the system fisrt.

Damaged coil Top View
1: Found that a coil under the PC Card slot was broken.
    Replaced and Test - No Fix

When peeling back the plastic near the Video connector- looking close I notice a cap is stuck to the plastic. Very small ceramic cap that was hardly noticeable without magnification.

Now- Where does if come from and where does it go?  What is it's purpose?

Under magnification, I view the area where the smaller components are and
see evidence of solder or tampering.  This appears to be the location of the missing/stray cap.

Since this is a multi-step repair...

Back to the work bench to see if the problem is fixed now.
Stray cap found near video conn.

Location of cap
Missing from pad
Replaced Capacitor


  1. think for info grited morroco in africa

  2. Hello,
    I have a Hp DV4-1225dx

    My problem is that when I power it up, it comes on and stays on, but I get no video and I get a continuous blinking of the caps and num lock light. I am a computer tech, but this project has me baffled. I ordered a new motherboard and it is doing the same thing, I switched out Memory chips(ram), and it is still doing the same thing. I even tried different Cpu's on both motherboard's, and I am still having a problem.

    Help me please

  3. You may have a defective touchpad or add-in peripheral. You should always test the board on the bench first. Without anything connected.
    Then do a visual inspection, carefully lifting plastics and have plenty of light, because they can remove parts from the board.

    The DV4 series reverts back to manufacturing problems. Switching over the the ATI video from nVidia simply swapped problems. Many caps and resistors on those boards have weak solder joints, from either flowing them too fast or contamination on the solder pads.

    Levi- you did not say what the blink code is. 1 Blink, 2 blinks or what. I will be checking over some of the DV4's that I have done and see what I can write up.

  4. Well when it blinks it just continuously blinks, I know that means power failure, but that's not possible when I added new bios bat, new battery, new adapter plug. One of the boards I just found out has a burnt capacitor, but the other one I'm still having the same problem.

    You say its the touch pad, when I plug it up i just plug in the aux power, and the power button and dc jack. then turn it on and get the same thing, I don't even plug up the touch-pad.

    I'm about to send this bad motherboard back that I just ordered and was already having a burnt capacitor. Should I get my money back or is this board a possible fix?

  5. You may want to notify the seller, and inform him that it is doing the same thing that your dead board does. Sometimes they write their ads on eBay so confusing that it said that it was a parts/repair board. But if the ad says that it is working, return it. Not knowing the capacitor that is burned, I cannot say if replacing it would fix it.


I cannot repair laptops for you via the internet, I can only answer questions related to posts. This is because I have not had experience on every motherboard that is out there. Bear with me.

If you do need it repaired. Contact me for quote (US/CDN Only)

Note: Only a member of this blog may post a comment.