XPS 1645 brightness adjustment isn't working

Hi everyone. I've noticed the brightness adjustment isn't working. I see the slider moving than I "Fn+up or down" but the screen doesn't dim.

Any workaround?

 

I remember some post either on the 1645 owner's lounge or the AC throttle investigation thread that said that he had the same problem and he had to get its screen replaced.

 

Same problem I had, Dell is sending a replacement as we speak.

 

Confirmed. It's a monitor issue. Dell tech representative. Replace the whole monitor and it fixed the issue.

Hope It might help someone.

 

i had a different problem. My FN up/down worked for a couple of seconds, then a red hue washed the entire screen and it just shut off. The computer was on but the monitor was dark. I rebooted a couple of times and started freaking out because the computer was working fine but I couldn't see anything. Eventually I pulled out the battery and put it back in and the screen came back on. Do you guys think I should get it replaced to avoid future issues?

 

exactly what happened to my pc...the only remedy is pulling the battery
and put back in...still waiting reply from dell support.

 

There's a way to force the monitor on before startup, maybe it could help rather than yanking the battery. With system powered off, Hold key 'd' and press and hold the power button. Don't know what this function all does, it tests/resets the display and/or is just a diagnostics test. It turns the LCD on for me before booting the system.

 

is this just with the RGB?

btw do you need a driver to be able to do that or is it built it into the mobo?

 

I just tried that on my 1737, and something happens. It looks really weird, kind of funky. And then, after the screen cycles through some colours it boots like normal.

It must be a new thing though, as it doesn't work on my old and broken (7900GS died) 1705. That just boots without the colours (but with all its artifacts )

 

Yup, same thing happened to mine. Got a dude coming in the next couple days to replace it.

Wonder what's causing it? Probably just a fluke. Glad it happened early in my warranty, LOL.

~Ibrahim~

 

OK, I don't know what happen, but my issue is somehow fixed!

I left the laptop on overnight to D/L L4D from Steam. I started playing and this is exactly what I did:

Played @ 1080p for about five minutes, noticed some heavy sound crackling.
Went into the settings and changed to 720p.
System blacked out with just a cursor and a crackling noise loop. Alt-tab'd to desktop and then maximized L4D again.
Was at the black screen for like 15 seconds, crackling noise loop disappeared, then the game came back.
I disconnected the AC adapter for good measure and I noticed the screen brightness change, which had stopped working since the screen "crapped out."
And then the brightness change started working again! w00t!

Debating whether I should call the technician to not come. I have noticed some backlight leakage lately...LOL. Maybe it's just me.

~Ibrahim~

 

1st: take my advice and never ever trust any dell tech! 99% Those guys has no clue about anything more than what is written in the manual! Also be extremely cautious when letting someone swapping screens on your computer. I wouldn't agree on that unless the screen has a hole in it.

2nd: I bet you that this problem will appear on your new screen as well.

3rd: To fix it, just shut down the laptop, disconnect the ac, remove the battery, hold power button for 10 sec, put everything back on and power up.

I am not sure what is causing the problem but is most likely to be something on a bios or firmware level.

 

#3 is about what I did and it seemingly fixed it.

~Ibrahim~

 

Thanks for the super informative post! i tried it your solution and it worked for me.

 

Strange, I had the same problem and they sent someone to replace the motherboard. That did the trick.

I have the RGB LED btw.

 

so, you got motherboard replaced and the other guy the screen. Both procedures fix the same problem? very interesting.

I think that both replacements required removing of the battery first, and this is what makes brightness to work again. However this problem is still there.

 

I think you're right. I couldn't adjust the brightness again (after the motherboard was changed), and I followed the battery removal method and this corrected the problem.

You were right about #2 and #3. I guess Dell sent a tech to my home and changed my motherboard unnecessarily when they could have just told me to remove the battery. Someone should tell Dell tech support about this fix...

 

Unreal dell wanted to send a tech out to replace my screen , I pulled the battery and held down the power button and it works fine . Im lost what this does ? Because I downloaded the latest Bios update .

 

thanks very good just screen replaced as color went all shades of green fair play dell was out next day replaced it not bad as o live in inverness a bit remote ..but then could not adjust brightness ,and have read need new screen again ..but tryed your fix and it has worked nice 1 ..have noticed also if you select dell save battery life option ,,you lose the enable transparency option

 

EASY FIX:

Unplug the power, remove the battery, hold power button for 10 seconds, then plug everything back... VOILA!

(I've had this problem for 9 months, and then randomly found this solution today while surfing on another forum)