Co-worker's HP Pavilion ze1110 backlight cuts out randomly but only on battery power. Why?!

[CZroe]

I've seen laptops with an intermittantly shorting backlight. I had to send my own Presario 1800T back to Compaq 10 times before they just gave me a different model (Over 20 times before the backlight problem). However, this is different: It ONLY does this when on battery power. It usually last a few minutes before going out as if it hasd to A"get hot" but it takes just as long if you unplug it after it's been powered on for hours.

The owner is the type that doesn't seem to care as long as there's a workaround (Using AC power). She let her warranty expire.

I'd still like to know what's up with that. I work on out-of waranty laptops every now and then and any weird problem I happen to be able to fix makes my job much easier. I'd REALLY like to understand this one.

 

[CZroe]

Bump

 

[CZroe]

Bump man BUMP

 

[CZroe]

Bump

 

[MDE]

Try cleaning the battery contacts?

 

[CZroe]

Hmm... Could there be contacts specifically for the backlight? I didn't think of that. I would think that if so the backlight's power would still pass through the same contacts while on AC power. I'll ask her to check that out

 

[zephyrprime]

Could it be a power management bug? Turns off the backlight even when it's not supposed to? A lot of power management is off entirely while on wall power so that could be why it doesn't happen while plugged in.

 

[DAPUNISHER]

Originally posted by: zephyrprime
Could it be a power management bug? Turns off the backlight even when it's not supposed to? A lot of power management is off entirely while on wall power so that could be why it doesn't happen while plugged in.

I think you nailed it, with my Compaq 900z on the default laptop/portable power profile it only takes 5 minutes of not moving the cursor for it to shut the display off, tap the touch pad and it wakes up.

 

[CZroe]

Well, it doesn't seem to be a power management issue because it goes on and off entirely unpredictably. I would imagine that if it were a BIOS/PM issue Googling would turn something up on it from other users, but, nadda.

BTW, DAPUNISHER: You're describing perfectly normal behavior