What's the name of the hardware device on a laptop that turns the monitor on and off when the lid is opened or closed?

My dv9000 laptop screen won't come on due to this 'switch' and I want to replace it. I know this is the problem because a few days ago the monitor came on without a problem when I opened the screen to use my external monitor. The screen was fine and worked great. I had swapped it for another screen and I had the same problem where opening the screen wouldn't power it up. I can't repeat the effect, so this switch is the cause. I just don't know what it's called.

It's NOT the inverter. I've replaced both the inverter AND the monitor to make sure. It's NOT the cables as they've been replaced and worked fine for three months before this issue occurred. It's NOT the graphics card. I've been using an external monitor for a while now.

I was going to let this go, but having the screen turn on fine after all this time, then go back to the not-powering-up state leads me to believe this problems has to do with the screen open/close on/off switch.

The computer itself is fine and always has been. This is a monitor issue. I just need a lead on the parts name since I keep getting told this is an inverter issue then case closed as solved even though it's NOT closed.

I apologize if this seems rude. I'm just getting annoyed that rather then an answer I'm getting a level one help desk reply then case close. It's quite infuriating.


This is typically a reed switch in the base that is used to sense the lid being closed. This works together with a magnet in the screen to sense that they are closed.

This page on the the support site seems to suggest that the reed switch is next to the power button in the base with the magnet opposite it in the lid.

It would appear that the component you are probably needing is known as the "lid switch board". Ebay has a few and Amazon used to sell them. The HP part number you are after is apparently 432993-001. If you Google that number (or contact HP) then you should find compatible replacements.

  • Thank you, I think I've seen that part in my laptop. I wish my rep was higher. You've saved me a serious headache. (Goes about fixing the problem) – Kayot Jun 13 '14 at 21:31
  • That forum thread also suggests that just disconnecting the switch should result in an always on display . . . – ernie Jun 13 '14 at 22:42
  • Well, it seems that it wasn't the on/off open/close switch. So, it's not the inverter, not the on/off switch, all the ribbon cables are properly connected. I'm letting the universe call this one. Thanks for the information. It's one less thing that could be wrong. – Kayot Jun 15 '14 at 18:35

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