How can I test the close cover switch on an HP zx5000 laptop
I have an HP zx5000 laptop with a backlight issue. The laptop will work on an external monitor, and I can see the dim desktop on the lcd screen when viewed with a bright light at an angle to the lcd screen.
The problem is that while this seems to be a classic inverter failure, I can sometimes get the laptop screen backlights to turn on by pressing the small lid switch pin. This happens occasionally and when it does the screen will stay lit for 10 seconds and reverts to an unlit screen.
I am still thinking its the inverter, has anyone else seen this?
The problem is that while this seems to be a classic inverter failure, I can sometimes get the laptop screen backlights to turn on by pressing the small lid switch pin. This happens occasionally and when it does the screen will stay lit for 10 seconds and reverts to an unlit screen.
I am still thinking its the inverter, has anyone else seen this?
nobus
you can try to remove /reseat the video cable for the lcd
ASKER
Sorry, forgot to mention that was the first thing I did.
I would like to know if there is a testing method for the switch itself, as I'm not sure if I want to put a multi-tester on it to check continuity, as that applies power from the multi-tester when testing.(don't know if thats an issue)
The switch also has four legs soldered to the motherboard, so its a guessing game which apply to the backlight.
I would like to know if there is a testing method for the switch itself, as I'm not sure if I want to put a multi-tester on it to check continuity, as that applies power from the multi-tester when testing.(don't know if thats an issue)
The switch also has four legs soldered to the motherboard, so its a guessing game which apply to the backlight.
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I'm not comfortable doing that, I don't want to pick the wrong 2 and short the board, that would be an even worse situation.
I guess I'm going to have to go with my gut and replace the inverter. Stay tuned, it'll take a week to get the part. Not an easy on to find as there seems to be many models.
I guess I'm going to have to go with my gut and replace the inverter. Stay tuned, it'll take a week to get the part. Not an easy on to find as there seems to be many models.
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>> I don't want to pick the wrong 2 and short the board << connecting a meter will not short the board, but you need to be cautious (like in replacing the backlight)
It might also just be the lid switch acting up.
I've seen a couple of laptops with similar behavior after a they've been dropped.
If you're comfortable enough with electronics - as you seem to be - you could check it's outputs, see if any of it toggles as expected (press/unpress - on/off output)
Also, how old is the laptop? If more than 2 or 3 years, than the inverter/backlight is also a prime candidate as you yourself have said.
I've seen a couple of laptops with similar behavior after a they've been dropped.
If you're comfortable enough with electronics - as you seem to be - you could check it's outputs, see if any of it toggles as expected (press/unpress - on/off output)
Also, how old is the laptop? If more than 2 or 3 years, than the inverter/backlight is also a prime candidate as you yourself have said.
ASKER
Thanks for the posts.
I began thinking more about the backlights myself Gary, it would be more difficult than just the inverter but certainly not impossible to fix. Easy to test though, I have a backlight stripped from another lcd screen that I can hook up to the inverter for testing, that should be a definitive test of the backlight at least.
Carlos, & Nobus. I would like to test the switch, and I'm going to come up with a method to isolate each of the switches legs and their purpose, but this is someone else's laptop and I am more cautious than if it was my own.
I'll be back.
I began thinking more about the backlights myself Gary, it would be more difficult than just the inverter but certainly not impossible to fix. Easy to test though, I have a backlight stripped from another lcd screen that I can hook up to the inverter for testing, that should be a definitive test of the backlight at least.
Carlos, & Nobus. I would like to test the switch, and I'm going to come up with a method to isolate each of the switches legs and their purpose, but this is someone else's laptop and I am more cautious than if it was my own.
I'll be back.
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That sound reasonable, I was trying to avoid a total stripping of the display as this model seems to have been superglued together by HP. I guess I don't have much choice.
Thanks.
Thanks.
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Update. The CCFL's are good, the switch is good(tested with multimeter for continuity)
New inverter has solved the issue. I guess I was reading too much into the intermittent lighting when the switch was activated. Inverter must have had a weak coil to allow it to light for the 10 secs then shut off.
Thanks all for the comments.
New inverter has solved the issue. I guess I was reading too much into the intermittent lighting when the switch was activated. Inverter must have had a weak coil to allow it to light for the 10 secs then shut off.
Thanks all for the comments.