Inspiron 8600 BIOS - Black screen workaround

Question

All versions of Inspiron BIOS I have loaded (A03, A04, A05) have exhibited this problem on my 8600. If I am running on AC and unplug the power (with my battery at 100%), my screen goes black. I can still make out some things in bright ambient light, but the screen light is off. Nothing but rebooting or changing screen resolution will make it come back on, not even plugging the power back in. I have tried this unplug test at the beginning of boot, before any drivers are loaded and it does the same thing, leading me to believe it is a BIOS issue.

I have found a workaround which may point to a solution by Dell. In the screen brightness settings in power management in the BIOS setup, you can set brightness levels for battery and ac power. If I set my brightness for battery to 100%, I never get a black screen; anything less, and I always get a black screen.

HMKrieps · Answer

So you are able to change the brightness between 8 different levels when on AC with the Fn+Up and Fn+Down (the arrow-keys) keys, but when on battery, the backlight is only on when you are on the brightest level?

mdavej · Answer

It's a little complicated. Here are the scenarios:

1. Dell Quick Set application running:

a. AC - Can cycle through all levels with Fn key normally.

b. Battery - Can decrease brightness 1 level down from max brightness and back up. If I go another level down, backlight goes out and won't turn back on.

2. Dell Quick Set application not running:

a. AC and Battery - same behavior as 1.b.

mdavej · Answer

Addendum: After some further testing, I can't cycle through all brightness levels on AC every time. Many times the backlight goes off even under AC.

Weese · Answer

I bought my 8600 3 months ago and have the same problem.  If I am running on AC and unplug, MOST of the time the screen goes black and the only way to bring the system back up is to reboot.  Dell Support emailed me and told me to upgrade BIOS to A07 which I did this morning.  I have unplugged a few times, so far so good.

mdavej · Answer

Turns out mine was a hardware problem. BIOS and driver updates didn't help. Only a screen replacement fixed it. Sounds like your problem is the same.

Weese · Answer

Forget the good news.  I was writting an email on AOL and decided to unplug the AC and the screen went blank.  I didn't know what to do, so I pushed the power button and heard AOL say good bye.  When I restarted the machine the screen was back.

Weese · Answer

Mdavej:

With the help of your postings I finally got dell to agree to send back my 8600 for repair. Thanks! The Technician looked at your postings and tried to track your case but couldn't without your Service tag #. If you are willing to send it to me I could e-mail it to him.

DELL-David W · Answer

All,

This does indeed sound like a service situation, possibly the inverter on the LCD panel. Something to try would be to press the reed switch above the NumLock or close the lid with that event set to "Do Nothing" in the Control Panel under Advanced Power options and see if that caused any change once released - hold it down for a couple of seconds. It might bring it back until further troubleshooting and service can be arranged.

It's interesting that there seems to be a minimum power level that the panel will accept on battery only.

Message Edited by DELL-David W on 04-29-2004 09:49 AM

Weese · Answer

Yes the reed switch will bring back the screen, at least when in is plugged into AC.  I found another thread with other people that have the same problem. They found as I did that BIOS upgrade A07 reduces the  frequency of this occuring but it doesn't eliminate it.  I have been in touch with a senor technician in Austin who arranged for my 8600 to be returned for repair.  It is on its way back now.

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Inspiron 8600 BIOS - Black screen workaround

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