problem with Power Management and display upon loss of power

[shailesh_paranjpe]

I am having 64 bit Kubuntu Precise 12.04 on HP Pavilion DV6 laptop with AMD processor.
I am off late facing a peculiar problem with display. When ever the laptop is on Charging and when power is lost, the laptop display disappears (Completely goes blank) This happens irrespective of whether the battery is fully charged and shows 100% or whether partially charged. The display is not even restored by the normal Alt+F1 and then Alt+F7 combination. In fact, I have not found any way how to restore the display, the only way I can manage is REISUB option (almost like hard start). This happens 100 out of 100 times when tested.
This problem also happens when the power/ charging is initially off and laptop is running and if the power is switched on. Many times, the battery manager is not showing the Charging/ discharging status correctly (i.e. it shows charging even when the power is off).
I dont know how to file a bug report since then display is lost upon loss/ regain of power. Please guide me.
Thanks.

[shailesh_paranjpe]

Does any body have any idea @ this one? I am really getting troubled every time during power loss or restoring of charging...
Thanks in advance...

[james147]

Not entirely sure I under stand the problem...

The laptops screen goes blank when you unplug/plugin the charger?

[shailesh_paranjpe]

Sorry for late reply. Yes, When laptop is running OK and the plugged in charging, and Power is lost, the screen goes blank. Sometimes, if the laptop is restarted without power/ charging and running OK, and if the charging is switched ON, again the screen goes blank. Please help

[Snowhog]

How old is the laptop? I'd be inclined towards thinking your battery is giving up the ghost.

[shailesh_paranjpe]

How old is the laptop? I'd be inclined towards thinking your battery is giving up the ghost.

It's purchased in October 2010. I suppose it is not that much old. The laptop works perfectly when directly booted under battery supply, i.e. charging is not switched on right from beginning and works for at least 1-1/2 hour smoothly. It is only when I am running the laptop i.e. booting done when charging is ON and then power is lost that I get the problem. (Also vice versa i.e. if laptop is booted on battery source and during running, the power supply/ charging is restored. Then every thing on display is gone... I think the battery is in healthy condition, what else could it be? Some power management problem?

[SteveRiley]

What's the output of

sudo grep -r . /sys/class/power_supply/BAT0/*

Also, I'm confused by "charging is not switched on." Does your laptop have some kind of feature in which you can connect the AC adapter but not allow it to charge the battery?

[shailesh_paranjpe]

Sorry for late reply.

There is no such feature. What I mean by the wording "Charging is not ON" is same as yours i.e. "AC Adapter not connected."

Apparently, now one of the problem seems to be solved (Automatically) i.e. When the laptop is running and then AC Adapter is switched ON during running, the laptop display is not lost. But the other problem is still there, i.e. upon loss of power during running, display is completely lost. I dont think that the battery is giving up since, the LED indication for ON status of laptop still keeps glowing. If I am in the middle of some operation (Such as file copy etc.), that operation is any way completed in the background (of course I come to know about it only after restarting with REISUB) This means battery is not giving up, just only display is lost.

As I mentioned earlier, resetting the display with Alt+F1 and Alt+F7 combination is also not successful. Is there any way out?

Thanks in advance.

[shailesh_paranjpe]

More updates information. My Kubuntu is dual boot but I use Windows 7 very infrequently. Apparently, I confirmed that such a problem does not happen when Laptop runs Windows 7 but happens only when running Kubuntu. So there is certainly nothing wrong with the battery.

[shailesh_paranjpe]

hello, can any one give a clue on the solution. thanks...

[SteveRiley]

Apparently, now one of the problem seems to be solved (Automatically) i.e. When the laptop is running and then AC Adapter is switched ON during running, the laptop display is not lost. But the other problem is still there, i.e. upon loss of power during running, display is completely lost.

I'm having trouble following your explanations. AC adapters don't have switches, so when you write "adapter is switched on," I'm not sure what it is that you mean. Furthermore, I feel I don't have enough details to understand what "loss of power during running" means.

Please try to write a step-by-step explanation of the procedure that causes a display loss. Include information about whether the adapter is plugged into the wall and/or plugged into the computer. I need to know the exact configuration of your computer and its accessories when the display goes blank.