Hp dv1000 display shutoff problem

[coffee]

Normally I do not have problems diagnosing stuff like this but this one seems to be kicking my keester!

Symptoms: DV1000 laptop display backlight shuts down after a few minutes. Display is still readable under bright light. Hitting the lid closed switch immediately restores the screen to normal. However, The time interval between screen shutdowns becomes shorter and shorter.





Troubleshooting: Replaced inverter. Replaced Motherboard. Disabled closed lid switch. Replaced screen.
I have yet to hook up to external monitor though. Not really sure what thats going to prove as this is a new MB in the thing. Replacement parts where performed by other tech but I double-checked them to make sure.

Booted Ubuntu live disk and experienced the same symptoms. Last effort was to swap out the pwr supply for my known good one that I use in the shop.

The only clue I have is that when first starting it will take about 5 mins for the display to shut off. Longer it runs the interval becomes shorter. I would think this would be an overheat issue however laptop seems to run fine and doesnt seem to get too hot at all. Fan running fine.

note: For the age of this thing its not really worth fixing but I cannot seem to quit on this. I have to know what the problem is. Im sure others get the same way on some things. Work is slow right now and I have the time too.

Your thoughts on this are very appreciated.

 

[anglian]

Could be the old DV NVIDIA chip issue.
I had one where tapping the screen would bring it back to life, a quick reflow fixed it.

 

[coffee]

I would like to thank you for your reply,

Thats why I replaced the Mother Board. But what is weird is that if I press the "lid closed" button on the laptop it immediately returns. But the longer its on the quicker it goes back to a dimm state.

Im starting to think I missed something in the heat sink or something that cools it. But the rest of the laptop works fine even though the display shuts down. I would think if its overheating the laptop would turn off or other problems would come up. ??

thanks,

 

[CraiGDaniel]

I'm having this EXACT problem on a Acer Aspire 5720.

Everything you mentioned happens. Only difference is it only happens when the charger is plugged in. Running off battery i don't lose the brightness!


Hopefully someone can suggest something and kill 2 birds with one stone.

Like you i'm not willing to give up as this is such a random issue and i want to put a fix in my head for later access if needed

 

[coffee]

Im having our parts deparment track down the original display and inverter on the laptop. Im thinking a couple of things right now:

1. The wrong display was put in the laptop. There is a normal display available and a "Bright Screen" display. Im thinking the bright screen display was put in by mistake. The inverter gets pretty hot when running it. Seems when it gets this hot the display cuts out.

2. Bad or incorrect inverter installed.

Perhaps the display is drawing too much power for the inverter and thats when it overheats and cuts out. (??).

@CraiGDaniel - I have heard of your problem while searching google. That is wierd that it does it with the charger plugged in. Lets hope we get two birds with one stone

Lets keep this thread alive until we come to a resolution.

Thanks again for all replies,

coffee

 

[Rob_NNCC]

IMHO when ever a back light goes out, it is the inverter, the screen or the cable from the inverter to the motherboard. Typically in that order. And yes, if you got the wrong screen it could be overloading your inverter and causing it to shut down. (think about it, the inverter overheats, it shuts off. you restart it by hitting the lid close button, but it is still hot so it shuts down faster.)

 

[shamrin]

I'm having this EXACT problem on a Acer Aspire 5720.

Everything you mentioned happens. Only difference is it only happens when the charger is plugged in. Running off battery i don't lose the brightness!


Hopefully someone can suggest something and kill 2 birds with one stone.

Like you i'm not willing to give up as this is such a random issue and i want to put a fix in my head for later access if needed

Just speculating here but this seems consistent with the overheating inverter theory. The machine is liable to be conserving energy when on battery power and therefore doesn't heat up the inverter as much.

 

[CraiGDaniel]

Just speculating here but this seems consistent with the overheating inverter theory. The machine is liable to be conserving energy when on battery power and therefore doesn't heat up the inverter as much.

There is a lot of heat from the invertor area of the screen. More so when the charger is plugged in.

Think your right you know.

Now how to fix it? ??


Sorry OP didn't mean to hijack thread

 

[bsil]

Just out of curiosity, does this happen when the battery is out of the unit completely and running only on adapter? If you have both the battery and the adapter plugged in, can you pull the battery and give the results. I saw something like this once, and it was a defective battery that was somehow causing the system to overheat, and "hibernate". Took the battery off, and there was no issue. Replaced the battery with a new one, and everything went back to normal.

 

[coffee]

You get to replace the screen with the correct one or possibly the inverter if you are able.

I have the pdf on the DV1000 and there are 2 screens available for it. One is a "Bright view" option. That adds to the idea that the "Bright View" draws more power and is overloading the inverter. Then the inverter heats up and shuts down.

@CraiGDaniel ---> Double check your part numbers for the screen and inverter. Go by the part number on the back of the screen. Not the laptop manufactuers part number.

My theory is the laptop had been worked on by someone else and the screen was replaced with the incorrect one.

Quote from HP DV1000 pdf:

Display assemblies (include wireless antenna boards and cables)
For use on HP Pavilion dv1000 models
373054-001 14.0-inch, WXGA, SVA with Brightview
367783-001 14.0-inch, WXGA

Have we killed 2 birds with one stone yet??

 

[CraiGDaniel]

Well.. bsil you seem to have come up with the magic solution!

Battery pulled laptop runs sooo much cooler and no screen shut offs. Battery was definately causing to much heat and inverter obviously couldn't cope.


Coffee - hopefully you can sort your issue now.. may be worth trying another battery / running without battery like me? If it's something you havn't tried it's not going to hurt to try.


Sorry for hijacking the thread a little.

Bsil i owe you a pint or two!

 

[coffee]

Coffee - hopefully you can sort your issue now.. may be worth trying another battery / running without battery like me? If it's something you havn't tried it's not going to hurt to try.

I do believe my problem is wrong screen. I have instructed parts to order the other without the bright view option.

Have a good one.

 

[bsil]

Hey glad I could help, and you problem is solved. Glad I had run into that oddity in the past, and it worked for you. I think I'll go pour a pint right now to celebrate our victory!!

 

[coffee]

Thought I would update the problem here that Im having with a DV1000. After alot of work I thought the problem might be a wrong screen in the laptop. However, Swapping out the "Bright View" screen for just a basic model screen didnt really have much of an effect. The display will still shut off but touching the "lid closed" button always turns the backlight back on.

Parts replaced at this point:
Screen
Inverter
Motherboard

Currently I have it hooked up to an external monitor also and the display on the external stays on. But its just the backlight on the actual laptop that shuts off. If looking closely you can still operate the computer.

I thought maybe the inverter was overheating from the "bright View" model of screen. Seemed like a possible problem. However that doesnt seem to be the case now. So Im kinda out of answers on this and hate to just through parts at it.

Possible other places to check? Firmware issue?

Thats my update for now.

 

[Rob_NNCC]

Did you replace the inverter before or after you switched to the normal screen? I had a toshiba that acted exactly like this when I replaced the screen. I finaly got a magnifier our and saw that the v. was different. I got the proper screen, and it got a little better, but was still bad. The brighter screen damaged the inverter so that it would overload even with the normal screen.

Just a thought.

Also, try running the screen at the lowest brightness setting. That will let you know if the inverter is overloading or not.

 

[coffee]

Did you replace the inverter before or after you switched to the normal screen? I had a toshiba that acted exactly like this when I replaced the screen. I finaly got a magnifier our and saw that the v. was different. I got the proper screen, and it got a little better, but was still bad. The brighter screen damaged the inverter so that it would overload even with the normal screen.

Just a thought.


Also, try running the screen at the lowest brightness setting. That will let you know if the inverter is overloading or not.

Thank you for the info. I just got back from running service calls. So, I should try another inverter. Well, Ill see if I can convince parts to order another inverter for it.

Hopefully that will do the trick.

Thanks again for your input