Laptop issue nec versa m400

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howler

1 post

Wannabe Geek

#6245 10-Jan-2006 11:46

HI, was wondering if anyone could help me.
I have a nec versa m400,
intel p4 2.8 ghz, 512 sd ram, 60g hard drive, 15 tft xga, with intel extreme graphics. with win xp home.

I have had it for 1 1/2 years and quite recently it has started to make the screen go black everytime I plug in the external power.
You can still see the screen, if you look really closely but only just. If you remove the power the screen comes on again.
The computer runs fine on an external monitor. it is only with the tft screen.

All the windows power managment settings are set to 'never' as I thought this maybe a power saving problem. A friend also suggested bios power managment, but I dont seem to have an option for this in my bios menus.

If anybody can help or has any other suggestion please could you let me know.

Cheers
Howler

tonyhughes

Hawkes Bay
8476 posts

Uber Geek

Retired Mod

Trusted

Lifetime subscriber

#26060 10-Jan-2006 14:45

laptops generally have a switch, so that when you unplug the power, the screen dims automatically. (to save batteries).

It sounds like that switch is faulty. (i.e. hardware fault, not software).

Where did you buy it from? I have been researching the Consumer Guarantees Act lately, and even if your warranty has expired, 1.5 years for a power socket on a laptop would probably be covered by the CGA, and the retailer would have to put it right...

[OOPS, I see you are not in New Zealand. Sorry, I dont have a clue about consumer rights in the UK, but have left my answer intact for any kiwis facing similar issues.]

greenjoe

6 posts

Wannabe Geek

#27898 6-Feb-2006 17:45

Sounds like a problem with your backlight inverter (that is a little circuit that produces a high voltage to power the small fluorescent light that lights up the screen from behind). A good clue is provided by Enchanted who points out that most laptops sense when the unit is running on batteries or external power and adjust the brightness to save power on the battery. You may find that the inverter is simply cutting out when the brightness is turned up. Experiment with this and turn the backlight brightness right down and then try switching between power and battery. I have seen exactly the same problem on a HP Pavillion notebook.

joe

jpwise

590 posts

Ultimate Geek

Lifetime subscriber

#27977 7-Feb-2006 22:47

As greenjoe said it's most likely a problem with the FL Inverter.

You can test it to some extent by plugging/unplugging the external power in your case, or cycling from LCD to external video and back (normally Function F4, or F5, etc.). If it lights up nice and bright, then goes dim all of a sudden it's most likely a crook inverter.

Jp.

Working for Service Plus - www.serviceplus.co.nz

Authorised Service Agent for Apple, BenQ, Sony, and Toshiba - warranty & non-warranty repairs.