HP Pavilion DM4 no video after initial post

[PaulTech]

Working on a HP Pavilion DM4 that had a cracked screen. Replaced the screen. Did a partial re-assembly with the RAM as I normally do before replacing the HD. Booted to YUMI -> chose Linux Mint. Started to boot (white letters scrolling by on black screen) and once the initial boot up sequence kicked in nothing further displays. The screen stays black. Same thing with Parted Magic.

Tilted screen past 90 degrees and same thing. Hard reset, no power, hold power button for 60+ seconds, same thing. Tried fn + f4 to try and toggle external to internal. Same thing??

Any ideas? Solutions? Is there a switch in the hinge or something like that which could be stuck? Thanks for the help.

 

[Captain Spaulding]

Working on a HP Pavilion DM4 that had a cracked screen. Replaced the screen. Did a partial re-assembly with the RAM as I normally do before replacing the HD. Booted to YUMI -> chose Linux Mint. Started to boot (white letters scrolling by on black screen) and once the initial boot up sequence kicked in nothing further displays. The screen stays black. Same thing with Parted Magic.

Tilted screen past 90 degrees and same thing. Hard reset, no power, hold power button for 60+ seconds, same thing. Tried fn + f4 to try and toggle external to internal. Same thing??

Any ideas? Solutions? Is there a switch in the hinge or something like that which could be stuck? Thanks for the help.

What happens if you try booting to the original OS? Can you see the BIOS screen OK? What happening if you plug an external monitor in?

I'm not sure why you would need to remove the HD when doing a screen replacement on a DM4 or remove the RAM?

 

[PaulTech]

Thanks for the reply. After a repair my standard procedure is booting to a Linux Distro and checking the display, keyboard/touchpad and WIFI. This is the first laptop I've worked on where after initial load it switched to the external video connection. After installing the HD and booting the BIOS and Windows driver used the new laptop video connection all the way through to the log in screen! Any insights on that behavior?

 

[Captain Spaulding]

My standard procedure is to check laptop model no, find correct screen, if it's one I have in stock great if it's not order the correct one. If it's a laptop that could have either CCFL or LED check the panel model no first by taking it out.

To replace the panel or remove it to check the model no:

1 Remove battery (never forget this step)
2 Ground yourself
3 Remove the rubbers on the bezel screws and undo screws
4 Pop the bezel off
5 Undo the screws on each side that attach the panel to the metal frames
6 Sometimes you need to disconnect the webcam, sometimes not
7 Lift the panel forward and detach video cable
8 Attach new panel to video cable and tape connection down
9 Follow the above steps in reverse to put it back together
10 Power it on, check screen and webcam

There are some exceptions to this where you have to do things like remove the whole display to get at the bezel screws but not normally. If I'm unsure it's normally possible to download the service manual, watch a YouTube video, or find a guide on Google showing the whole process for the particular model of laptop I'm working on.

No need to mess around with removing hard disks or memory or booting from Linux cd's. I love screen swaps most can be done in 20 mins max, easy money. I can have a screen done I have in stock while the customer waits, this is great when they have been quoted 3 days or more from somewhere else, you then have a new customer for life

 

[JustInspired]

Working on a HP Pavilion DM4 that had a cracked screen. Replaced the screen. Did a partial re-assembly with the RAM as I normally do before replacing the HD. Booted to YUMI -> chose Linux Mint. Started to boot (white letters scrolling by on black screen) and once the initial boot up sequence kicked in nothing further displays. The screen stays black. Same thing with Parted Magic.

Tilted screen past 90 degrees and same thing. Hard reset, no power, hold power button for 60+ seconds, same thing. Tried fn + f4 to try and toggle external to internal. Same thing??

Any ideas? Solutions? Is there a switch in the hinge or something like that which could be stuck? Thanks for the help.

We had a Compaq CQ61 (same as HP G61) with a similar problem this week. Backlight worked outside Windows but switched off when booted into the OS.
We never did try a Live CD because we found the problem before testing further.
It was the magnet for the lid switch. It had come out of its little plastic holder and was triggering the lid switch even when the lid was opened.

So. Yes, I'd check a possible lid switch issue.

 

[PaulTech]

Thanks for all the great feedback! I checked out your website and saw the quick turn-around comments for screen replacements. Sounds like you've done the research. Is there a base group of panels (i.e.
LP140WH2(TL)(A​​2)) to stock that work for a high percentage of laptops out there? I wouldn't mind starting to stock a few since as you mentioned the ordering process creates the delay time.

 

[Kitten Kong]

Hi Paul, there was a thread only a couple of days ago, where we went through the most current screens required. Have a quick search, and i'm sure you will see it.

Save bringing up the same details all over again

 

[PaulTech]

Thanks!

Found it: http://www.technibble.com/forums/showthread.php?t=49538