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Dell Inspiron Laptop Flickering

I have a Dell Inspiron 8200 and it is starting to flicker -- I tried to change the power cord but that did not seem to help -- also I have 90W power cords -- but my system only recognized them as 70W  -- I have 3 power cords and I get the warning message on booting up so I have to press the F1 key to bypass it

Thanks
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rid
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...the waring message...  What warning message?

The flickering may be either a failing backlight tube, a bad inverter or bad connection between case and lid. Does moving the screen (bending the hinges) affect the flickering at all?
/RID
What your expierencing is a bad charger board on the motherboard, i have seen this many times where the system will faisl to recognize the ac adapter as 90w, it is caused by a bad ac adapter or charger board and since you have tryed known good ac adapters then the issue is the charger board on the motherboard, and the only fix is to replace the motherboard (the charger board is part of it). The flicker is being caused by the inconsistant power the charger board is providing. If the system is out of warranty you can find a motherboard on ebay motherboard from a dell latitude c840 and dell precision m50 will work in an inspiron 8200.
rid is right.
Your AC power supply should have no affect on the screen flickering unless you have no battery whatever.

What jamietoner said is true too but that condition shouldn't cause the screen to flicker..

What warning message?

You may have more than one problem....

At least some Dells have a BIOS setting for default brightness that can be different for battery or AC power. Possibly this could be the power brick folding intermittently or just not delivering properly, causing the brightness to fluctuate. In which case I stand corrected and this is a power adapter or MB problem.
/RID
rid
That makes sense too.
I wanna better description of this 'flicker'.

I've seen Gateways with the same brighness settings in the BIOS. May be very common.
...better description...
Yes. And it might be interesting to know if it happens only with AC feed or even on battery power only.
/RID
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ASKER

Hi everyone -- sorry for the delay, there are actually 2 issurs going on here 1. When I boot up I get a message saying something to the effect of -
Warning  70W (20v,3.5a) Ac Adaptor detected system will not be capable of running in full performance modes without a 90w (20v, 4.5a) AC Adaptor
But the thing is, all my ac adaptors are 90W -- also, the battery does not work -- I purchased another one off of EBay in December -- but it only worked like 2 days and is dead :( waste of money.

The flickering issue -- last night it only flickered a few times -- flickering means that it flashes to black and back to the screen -- 2 nights ago -- the computer was working but I was not able to work on it because it was flickering so much -- so I backed up my files and turned it off. It was a lot better last night -- I was not able to detect a difference when I moved the power cord around because I did that a bunch -- once it seemed to fix it for a minute or so -- but then it was hosed. FYI -- I have had this since 2000 so it could just be old -- it has been use a TON. Thanks all for your help
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rid
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Michelle, the batterys not working because of the adapter issue, the system will not charge the battery when it detects a 70w adapter (so i doubt its a problem with the battery you just purchased), and where its the charger board thats causing the issue (because other ac adapters display the same issue) it may not switch to battery power either. I have seen this issue be accompanied by the lcd flickering before, its all being caused by a bad charger board on the motherboard not supply consistant power. I would suggest getting the motherboard replaced as soon as possible, I have seen this problem take out hdds, lcds, memory, and cpu's if left running in this state.
Thanks-
Do I need to send it into Dell then? These are depressing scenarios -- but better than lose my system completely I guess -- so if I change the motherboard -- it will fiz the ac issue and the battery issue and possibly the flickering -- to answer the comment from RID -- it has been over a year since I have actually used the battery without the adaptor -- it is a bummer because if the cord ever accidently gets unplugged -- my system shuts completly off :( sseh. Thanks
YOU NEED TO STOP USING THIS LAPTOP!!

Both rid and jamietoner are right. - I'm just going to elaborate some.

You have two issues which may or may not be related.

The screen:
LCD screens are built in layers. One of the layers has tiny diodes that change colors. They do not emit light, they just change colors so you cannot see them without a backlight behind that layer. (The image could be there but the screen would appear black.)

The backlight circuit has two parts (besides wires).
(1) The tube(s) which are called Cold Cathode Tubes. Typical screens use 1 to 3 of them. (Most laptops just have one or two.) These are very similar to florescent tubes.
(2) The Inverter. This converts voltage from the laptop's power distribution into a high voltage (900 to 1300 VDC) to power the Cold Cathode Tubes.
- When you screen goes black the likely problems are the tubes, the inverter, or loss of power to the inverter.

The battery / AC adapter issue:
The AC adapter or the battery provides raw power to the laptop's power board or equivelent circuit. This circuit splits out power into different voltages for different things inside the laptop (drives, fans, motherboard, -LCD INVERTER-) and controls the charging of the battery. (If this circuit board is removable it is called a 'power board' or a 'charger board' by some makes. Many (maybe most) laptops have this circuit built right into the motherboard.)

- Your power board (or circuit) is bad. That is why the AC adapters aren't identified correctly and why the batteries won't stay charged.
- The problem with the power board MAY also be causing the problems with the screen by causing the inverter to loose power.

It would be a good idea to stop using this laptop -NOW- until you have fixed the problems with the power board.
If you don't, as jamietoner said, you may cause more damage to other parts of the laptop including the memory, drives, processor,......

- If the power board section is not on it's own circuit board then you will require a new motherboard.

PCBONEZ
.
so does it go to Dell or will that not help? Sorry if I am lame but I am not technical -- it just sounds like I need a new laptop -- can I get another dell or do you guys have other suggestions that are better -- i just love my dell :(
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gee -- thanks everyone -- just a bunch of bad news on top of bad news  -- but on a lighter note I have a credit card :)  guess who is buying a new laptop before all of my information is hosed -- not sure how to assign point -- so feel free to yell - I appreciate all your advice
I'm quite satisfied with the points and I hope you find something useful at a good price.
/RID