computer keeps going on and off of AC power

There is a simple to use method to see, if it's your software, or the hardware:
Take your Ubuntu Life CD and boot from it.
Work with it about two times as long as you do, untill the error usually appears.
If it doesn't happen, something with the software went wrong.

If it happens again, I would think that it is a hardware problem (and it is not allways the cable, only in 95% of all strange behaviour of computers <g>)
It also might be a problem with
Your AC supply itself (not enough Watts ?) Do you use many USB devices with no extra power supply (extra hd, fancy little lamps, dancing bears <g> etc.) Unplug and if the error is gone either go and get a AC with more Watts or extra power supply for the HD.

It might be a problem with the wall outlet where your power supply is conected to. (try another one and if this solves your problem call a professional to look after the wall outlet, this can be dangerous!)

It might be a general power problem - do you see the light in your room sometimes become darker / brighter?

sorry for replying so late...

Ok, 1. I don't have an Ubuntu Life CD, had it but moved and can't find it. Any suggestions?

2. The AC supply is fine because the problem not only occurs at home but everywhere I plug the PC to....

3. I don't use any usb devices...Dancing bears???

I hope this helps you help me.

Another thing I updated my system the other day and It's been almost a week with out any problems until yesterday when it started doing it again on/off, on/off the AC. Then suddenly stopped and it hasn't done it again...

Thanx!

1 To get a life CD use http://www.ubuntu.com/getubuntu/download
It's always good to have one, because you can get access to your computer end even repair damaged boot entries (which will prevent your aptop to start), manipulate partitions and so on.

2 this reduces the problem to a problem of your laptop.

3 dancing bears is only an example for useless and silly things, one can plug into the usb device.

When a problem comes and goes in irregular intervals it only makes it more complicated to nail it down. <sigh>

It could be the RAM.
With the life CD:
boot your computer with the CD and chose the checking RAM option.

It could be a thermal problem.
When your laptop has a certain temperature (inside) the error occurs. If it is colder, it would not, if it is hotter it would not either. Unfortunately the temperature depends on the temperature in the room you are, on the programs you run and how processor intensive they work (some games transfer your computer into an oven) and on the time, you are working. Does your cooler work hard, every time the error occurs, or doesn't it work at all?

But this should have been detected by the service team.

hi, me again

problem continues I even install a newer version of ubuntu 9.04 and the problems continues...HELP!

Hi Valkyrie,
sorry to hear that.
But I think this is really a hardware issue.
You should carefully check, the uptime, when the error occurs (for example if it needs 2 hours, untill the error occurs) and have your laptop checked with this information.

I have taken my laptop and AC cable to be be ckd, and they said the same thing as before....It's a software issue. Problem here is that Toshiba's come with windows and they do all their testing with a widows CD and they state it works just fine. I tested the PC when I picked it up as always it worked fine, it charges normally with a other cable and the cable charges other computers fine, but as soon as I get home...tada! problem remains....

Just now, it did it again and I just turned on the PC.

I implore your help!!! Is there anything else I can give you as far as information? I really don't want to go back to windows!!! but if this problem continues I'll have to, I just can't keep this up, not knowing when my pc will run out of battery and not charge again!

To tell the throuth, I'm running out of ideas.
Only one more:
You should try to upgrade to Ubuntu Karmic 9.10. This could be a solution for itself or if not it would make much more sense to report a bug on the newest version of Ubuntu.

Simply go to System / Administration / Update Manager and it would give you the opportunity to Upgrade to Karmic.

Well I don't want to update top the 9.10 because it has given people I know problems...one of them almost lost all his data...so . . . No thanx!

I took the pc to someone who knows ubuntu and he solved the problem by disabling the API or something like that, advanced power something I think it's caled, thing is it worked. Only thing was that it has a side effect: the front volume control on the pc doesn't work and i have to shutdown manually, but other than that it's ok.

Thanx so much for all your help. I wish I could post what he did so it could help someone else. If I get the whole procedure I'll posted as a comment so I won't close the question just yet.