8730w dim screen - can't make it brighter anymore

Hey folks,

So I've been using my 8730w off an on for several years now, but in earnest now only for the past year or so.

I'm having an issue with screen brightness and I sure hope the video card isn't defective.

I just can't make the screen brighter (it's at 0% according to the HP Mobile Display Assistant) and stays dim even during boot up. Of course the function keys have no effect whatsoever. I've reloaded older registries, no no avail. When it got stuck before I would just reboot and get the function keys working again, no such luck now.

We did have a major power failure before this happened (power just came after over a day) and I had the computer plugged in when it happened, but it never skipped a beat. Shouldn't the power supply brick filter out transients? In any case everything else is working fine.

So here I am, can't use the computer except in the dark now, and it's a pain in the a$$.

I have tried boot diagnostics, but there is nothing for testing the video card. The HP Mobile display assistant is no help whatsoever. I get my setting of 50% but it quickly disappears and gets replaced with "0%". I am a bit worried because at some point in my diagnosis, the screen stayed black and I had to force shut it down, and when it came back, it was flashing red and blue even during boot, but that eventually stopped by itself after a couple of minutes.

I am very annoyed because not only did I not use that computer much, and certainly not on demanding applications (it's mostly word processing), but it was much more expensive than my older 'consumer' Toshiba that still works like a champ 7 years later, albeit with a cracked case. Furthermore, my touchpad buttons are completely worn out and I haven't been able to find a replacement. Considering the issues I also had with the Dreamcolor screen, I'm quite disappointed. Business class? Warranty coverage wise yes, but in terms of hardware quality it has been disappointing experience and since I REFUSE to be aggravated by Windows 8 and am probably stuck trying to find an older machine, I am at a loss as to what to do next.

Any ideas? Is my video card knackered?

 

I guess you are not able to try an external display or TV? If that would work you know that it is not the video card.

You can try to re-install your BIOS (just install the same version which you already have), some settings are set to "normal" (I had to do this twice within a year or so after the head phone jack audio was not alright). Normally resetting BIOS to factory settings does not help (in this case I had). BIOS-installation you can download from hp.com (driver pages).

You can remove the battery and power plug and press and hold the power key for 30 seconds. This could help to reset some settings, too.


I guess you know, pressing (and hold) the FN-key and f11 key switches the light sensor on or off (this should even work in BIOS), FN-key and f10 should increase brightness. If this both does not work even in BIOS setting screens I don't know. Is the light sensor set in BIOS to on or off? Or do you have none at all?

Dreamcolor has three LEDs for beacklight? (red, green and blue) or just white? If the LEDs won't work at all I guess you see a black screen only. If you still see something, there is hope... but really hard to tell, sorry.

Do you still have warranty? (there must be somewhere on hp.com a page where you can check this)

 

Thank you for your quick reply, Sotton, Old Man ;-)

I had completely forgotten about this forum's aggravating log-off after just a few minutes and my carefully crafted reply is now gone Man, I hate that! Anyway, back to notepad for me...

I do have a 20 year old CRT, but it has sync issues. When I drove it using the docking adapter, it worked fine, but I was never abvle to drive it at higher than 1600x1200 (although the screen works fine at 2048x1536), Anyway... I'll try that, good point.

In any case, the problem is not the LCD itself, but the brightness control. I can still see the screen, except that it's now much dimmer than a sheet of paper , in effect at 0% (minimum) brightness. I've included a picture here:



As you'll notice, the screen is significantly dimmer :-( I can manage, but only with the lights off. This picture was taken with the lights on.

Also, if you look at this video, elitebook LCD error - YouTube, between 0:56 and 1:11, you'll notice acting on the brightness as no effect whatsoever, excatly what I am experiencing. The only difference with me is, his screen appears much brighter than mine!

Thank you for the BIOS suggestion. I did reset the existing BIOS, to no avail. What bothers me most is that the red/blue flashing (like a cop car flasher, LOL) happened even during POST AND BIOS setup, so I'm afraid that it may be a hardware issue, but you are right, it could also be BIOS or firmware related.

I removed the battery overnight. I figure power should have drained after 8 hours? Anyway, thanks for the advice, I will try that.

No effect. I have not seen any settings for brightness in the BIOS...

It is a DreamColor display (RGB led), weren't you one of the early adopters of that laptop back in the days (2008-2009 or so)? As for warranty... It's expired for a year now :-( If I knew what was wrong I could then decide what to do...

Anyway thank you for your input, it's much appreciated! I will try your suggestions and get back to you.

 

Before I go ahead.... The BIOS revision I just found ends with is F20 and is a year more recent than the version I have (F12). My question is: is it reversible? I've heard horror stories of not being able to install old OS after a BIOS update... Not that I care much at this point

Never mind... I got my answer... "After installing this BIOS version onto the system, prior BIOS versions cannot be installed onto the system" they call that an "enhancement"? thanks, but NO, THANKS! will try F13 instead...

 

yeah, I have my 8730w since 2009 but it has the normal WUXGA screen. This Dreamcolor screen is different in a few ways. It could be some kind of calibration problem or a hardware problem.

BTW, I meant I can set screen brightness even in the BIOS setup screens with the function keys (there is no on screen display like in Windows of course).

I have no problem with BIOS F20 but I doubt it will cure your problem so no need to upgrade (however, if nothing helps this could be one last try)

 

No effect...

If I knew that it was a video card issue I'd get another one, replacing the motherboard OTOH just isn't woth the trouble for me. As I depend on a bright, clear screen for doing my presentations, I'll won't have much of a choice but to retire it. If you have any suggestions, I'll gladly listen.

I'll pass for now, as it's irreversible. I'm sure Microsoft paid HP big bucks to lock the BIOS to accept Windows only. Really upsetting coming to terms with the fact that the personal computer revolution is over, and that users have lost to corporations. Just like in politics. It's really depressing.

 

if you cannot change the brightness when in BIOS I guess something really is broken. (It could be that your fn-key is broken but than you must be able to change the brightness with the slider in windows (energy adjustments) which you are not able to, as I understood it. fn-key and sleep (f3) or other fn operations do work, i guess?).

Never heard that if the video card is broken it affects the brightness so I doubt it is the video card (but could be, I am no expert)

Still there is a small chance that you only have to reset a value and all is back to normal. But if one LED is dead I am afraid it is beyond repair (?)

 

Thanks for the information! but I wasn't far off, curtailing user freedom...

Thanks for your opinion and thank you for the reasonable explanation. But considering the proven track record of our government, that of the corporations whose agenda it has been serving in the past fifteen years and the great loss of liberty people have had to endure as a consequence, we should all consider anything that has the word "security" in it with great suspicion. Just remember, those who would trade liberty for security deserve neither.

 

Yes, all the keys work; the brightness slider works as intended, just that the actual brightness stays at 0%. The ambient light sensor is non functional as well, shining a light on it when on has absolutely no effect. In HP Display Assistant, brightness setting says "50%" during initialization (but no effect on brightness whatsoever), but as soon as it recognizes the Dreamcolor panel, the slider sets itself at 0% and greys out.

For this reason, I am not 100% sure it is not software or at least firmware. Unless the display assistant measures the actual power output from the LED driver board/ambient light sensor/motherboard/screen?

The LEDs are all functional, as the colors are perfectly fine, it's just that the INTENSITY is at minimum. Here is a picture that shows it, of course it's compensated for the low intensity (notice the grain!), but you get the idea:

 

have you tried a different power supply? I know that the Dreamcolor display uses more power but this can't really the problem. Just one other possibility to check...

If you do not had the Dreamcolor display I would suggest to check the so called inverter. But I think these are for CCFL only. However, there could be some similar thing to control voltage and so the brightness which is broken (and hopefully replaceable) Maybe check if there is something as a replacement part for Dreamcolor displays, too?

 

I have tried absolutely everything I was able to read about and think for myself... I've listed practically everything on the HP support forums here

I have removed the bezel and removed the ambient light sensor module, but doing so totally blanks the screen. In other words, if the screen is dead, it could be a bad ambient light sensor module. What makes me think it's not the module and probably the LED driver module is the fact the red and blue LEDs went wild for a while in the early phases of restarting the computer after the power failure, before going dim again. Anyway since the RGB LED driver is integrated into the display, from the spec sheet, it looks like if there is a problem there, the whole display will have to be replaced.

Looking at the LCD panel itself does not reveal anything apparent, apart from the fact that when I had the panel replaced under warranty a few years ago beacuse of the pink and blue tint at the lower corners, the tech damaged some of the torx screws and never bothered replacing them, so it was difficult to remove some of them. What I liked is that the laptop cover itself is very nicely made, out of magnesium (it's actually printed on the recycling symbol). The front bezel, otoh, is a flimsy disgrace.

I wish I could find a diagnostic tool that would go through the whole hardware. I'd then know for sure what's wrong before replacing any parts.

So what do you think, ambient light sensor or LCD assembly?

 

With switched on light sensor you still can adjust brightness (at least with the normal WUXGA)

So, if it is broken, brightness control could still work but only on a normal (light sensor always off) or darker level (light sensor always on or broken)? I don't know. Maybe a broken light sensor gives the result you have.

However, the light sensor part 495029-001 for the Dreamcolor is not that expensive and if you think you can do the repair, it is worth a try. A whole Display is too expensive.

 

I took a good look at the sensor and the components are quite large on it, discrete SMD transistors and capacitors, it just doesn't seem possible for it to have fried like that.

However, I always come back to this red and blue flashing screen for a while, that would indicate that something went amiss with the RGB backlight subsystem. So logically, it should exclude a problem with the motherboard. Then again, it's not impossible, considering it happened during this power failure or right after, since connection to a power supply does normally increase brightness. But I could be wrong mistaking the cause for the effect ;-)

As I don't have spare parts to play with, have not found anything like it online and have not been able to get low level diagnostics tools to figure out where the problem really lies, I'm kind of stuck. Considering this is my work computer, it's quite distressing, and I dread even thinking about getting a new machine, considering how much it's been to get this one to work the way I want with my legacy software, some of it 20 years old that has no modern equivalent...

Anyway, thanks for your help, Man. I guess I'll be looking for another 8730w on eBay and hope for the best. As for screens, I may just get a new one, just need to find a vendor who will accept returns, should this prove not to be the problem.

 

I just found a page with lots of video bios information and found a bios file and utilities for flashing the video card itself. Why I haven't found anything about the video card is beyond me, why would HP not even talk about it just boggles my mind.

Anyway, I always come back to the weird flashing I experienced and, now that I remember things in greater detail (it only happened so briefly I had forgotten about it), I did at one point in the process get a screen where resolution and image were all wrong, with identical screen images stacked on top of each other, which would indicate something was wrong with the video card.

Furthermore, one person who had a flashing red blue screen in an unrelated internet post said that although the video was on an external monitor, it tuned out his video card was indeed defective and that his issue was resolved after replacing the video card.

Then, I read about people baking their video card, reflowing the solder, resolving issues that way, and that it is quite frequent with some nvidia cards.

In other words... I am staring to take a fresh look at the video card

Of course, it could also be as mundane as a loose cable, even though there was nothing obviously loose at the screen end and the computer did not fall or suffer any mechanical stresses.

So, what do you think, flashing the video bios, shouldn't it be worth a try, or am I going to fry it?

I have tons of urgent work to catch up to so I will most probably not have any time to delve into this for the next few days, but I'd love to hear your opinions on this.

 

I once had a broken video card and it behaved way different but it could always be the video card, of course.

Which video card do you have, BTW?

Anyway, if you ever want to try the to exchange the light sensor board here I found where you can get it

HP Parts Store - HP Computer Parts, HP Printer Parts and HP Compaq Parts

 

Nvidia Quadro FX 2700M... How different was your video card problem?

Thanks, but $1100 for the Dreamcolor screen or video card, are they nuts? At least for the sensor, $20 is reasonable. Thank you for your help, I'll keep the info handy.

I've got to get back to work, deadline is driving me nuts, plus my truck alternator belt just snapped, it probably suffered from having run the alternator under high output for too long with the inverter running the freezer during that power failure Keep in touch!

 

yeah, my FX2700M broke during gaming. I am not sure if it just overheated (it was an excessive session ) or if it was one of the problems NVIDIA had with quality (dieing cards). Maybe both...


My problem was that only vga resolution was possible cause the card was no longer recognized. Further, I had strange pixels all over the screen.

Like this

http://www.avforums.com/forums/atta...raphics-card-dead-dell-studio-540-example.jpg

so, from my experience I doubt it is the video card, still I will not say it is impossible.

Another thing you can try is to look for the normal WUXGA screen (with CCFL). However, this is no substitution for the Dreamcolor and it is maybe not available near your place (I speak of ebay of course, in the last months I saw at least two offers of the full LCD lid and LCD with hinges and all for about 80 Canadian Dollar.)

 

I had a similar issue with my first 8530p - the brightness would stay at minimum no matter what. The difference is that the ambient light sensor worked - it would go to maximum if I shined a flashlight into it.

It was NOT the drivers, BIOS, video card or motherboard - replaced them all. I'm 99% sure it was the inverter.

Then I upgraded to 8GB of RAM, which required me to take out the CMOS battery and hold the power button for half a minute (then insert the 4GB modules one by one, because inserting them both and powering up would result in a black screen and blinking LEDs). The brightness worked fine again...

It failed again for a day half a year ago - worked fine after power up the second day.

Weird doesn't even begin to describe this...

 

This is exactly why I am not discounting the video card, as several people who have had the "red green blue" or "red blue" flashing (especially on Dell laptops, apparently) was caused by bad solder. In one case also, there was no problem with the external video and it WAS a bad card.

And since I found one on ebay that the seller was very nice and helpful with my problem, I just went for it was lucky enough to get it for less than $20 (plus shipping), so even if it turns out not to be the card it won't be a big loss

When I had the red blue flashing, at some point I did get just weird double desktop squashed horizontally, you know the kind we used to get with old TVs and CRT monitors... That is definitely video card! It only happened for one boot, while the red blue flashing happened for several boots. The whole drama lasted maybe half an hour...

I kind of tend to sway towards the video card at this point, but I do not disagree with your assessment. But for $20 plus shipping, what have I got to lose?

I did find a source for new Dreamcolor panels for under $100, so that is definitely the next thing I'll be looking at...

 

So, WAS it the inverter? How did you resolve the issue?

The thing is, the Dreamcolor panel does not have an inverter, but an RGB LED driver on the back of the panel itself so if that is busted, the whole screen needs to be replaced...

Interesting, that would indicate a problem with RAM.... I did try the 'hold the power button while battery removed' but that changed nothing - Of course, I did not remove the CMOS battery... Looks like it's deep in the innards of the laptop... I also removed both RAM modules and switched over, but that didn't help... Perhaps I should just remove one RAM module at a time and see if that heps? Hmmm! Worth looking into!

Agreed... It's the most frustrating thing, because diagnosing it is so difficult... I wonder how HP does it!

 

I didn't - I was thinking about buying a new inverter (also opening the display assembly is a pain), but it just "fixed itself" after I received the new RAM and installed it.

Either the BIOS/firmware malfunctioned or the inverter is slightly damaged (very unlikely for a transistor to get stuck temporarily, plus the circuit is the same for the manual brightness and light sensor)...

I think it's the former since HP have a penchant for weird custom design (quad cores don't work well even though the boards are fully compatible hardware-wise, MXM implementation is weird, cards are whitelisted, etc.).

Also flashing the BIOS doesn't change most settings - there's a shadow copy on the chip (which makes restoration from a completely botched flash possible).

 

Now I understand... That would be consistent with draining the CMOS using the power button with battery removed if there was something corrupted in the BIOS, nothing to do with the RAM, unless of course, the old RAM was defective... As for playing around with the RAM it did nothing for me... But if the manual brightness control is on the same chip as the ambient light sensor and neither work, as is my case, then it would appears that the ambient light sensor module might well be the culprit after all...

 

Well, it's not the ambient light sensor.

I just replaced the sensor with a spare I purchased, and it has had zero effect on brightness control.

Funny thing is, the screen went all weird on me for a bit with totally gaudy colors, à la 16 color with wrong palette, and I only got rid of it removing the Nvidia card from within Device Manager in Safe mode.

Since there was no change, I tried the old sensor again, no difference. So I guess we can strike that one out.

I really wish there was a way to diagnose the components without purchasing new components and trying them out... Am I going to have to purchase another 8730w just for this?

Considering the problem happened after this big power failure we had, I am starting to think that maybe the problem is related to the power supply on the motherboard, and I'd like to hear what you guys think. I know this is not a hardware tech forum, but it doesn't hurt to ask, besides there are many smart people here ;-)

Since I just couldn't wait for a solution and need a laptop I can be productive with and since I could not find an 8730w with Dreamcolor, I purchased an 8740w with DC2 online (I would have preferred not going through this expense), which I just got today and I will admit that the Dreamcolor 2 is nicer as far as angles are concerned and has better evenness than the DC1 (no pink bottom left corner) and outstanding brightness (can easily use it outdoors at midday), a must to me.

I will post a comparison between the 8730w with DC1 in the 8740w with DC2 for those who might be interested in acquiring one of the two.when I have the time.in my other thread..

So - How do I test a motherboard/ power supply input for problems?I don't think it's a fuse, as I would probably have no backlight whasoever... What's your take on this, are there any utilities that do real low level diagnostics that could pinpoint the most likely problem area?

 

So, I wasn't going anywhere solving my problem and since the 'new' 8740w developed a hard drive failure (fortunatley still under warranty!) I am looking further into my 8730w and what I could do to fix it.

So I was reading and found the specs for the laptop screen and noticed, looking at the schematic, that there are EEPROMs on the thing, and that these things have specific data written to them!

So I downloaded a utility to read the EDID, didn't work, so I looked into the registry and found, where the laptop screen is listed, under parameters: BAD_EDID, with NOTHING in memory, all zeros!

Could it be that the power failure wiped out the EDID and that rewriting it with the published manufacturer data will restore full screen functionality?

I looked further in the registry and reloaded a copy I had saved when I had my last service done under warranty by HP... Lo and behold, it lists THREE LG LCDs in there, and I know for a fact that I had the screen replaced twice... For a total of three screens...

So my question to the experts and anyone who may have an opinion is: could I simply rewrite the EDID to the screen using Powerstrip so as to restore the lost brightness functionality, or will this require a hardware fix with a JTAG or something similar?

 

So my problem is finally FIXED... It WAS the screen after all!

I was fortunate enough to locate a broken 8730w that had apparently fallen off a moving vehicle, fortunately in the closed position ans as luck would have it, with the EXACT SAME MODEL NUMBER AS MINE! Good screen, video card, cable, ambient light sensor and a motherboard with 4GB of RAM with a broken SATA connector (but all the pins are in good shape, only the plastic connector is broken off). HD was literally ripped out of it, DVD is a goner as well, and the case has abrasion marks and there is no bluetooth module and no cover either. Pictures will be added as I fid the time for it.

You were 100% right . I hesitated getting just the screen because of the hassles to return it should it haven proven to be something else, because Canada Post REALLY takes us to the cleaners with shipping. I mean, it's out of this world. I positively DREAD using them. Their prices are beyond outrageous!