laptop supply

[Cuc Tu]

after a couple hours use, my laptop started going in/out of bat/charge mode. When in bat mode, the display dims.

The charger was warm, which seemed normal. Could this supply be failing now or possibly something in the laptop?

[Cuc Tu]

i'm wondering if the laptop is switching to battery because it's charged, and this is normal.

it seems not normal because it went on/off a few times in a short time ~1 min.

[jlreich]

Sounds like typical problems when the power port on the laptop is getting a short in it (solder coming loose). It could also be the adapter is going bad or the cord is getting a short in it. If the adapter has an LED on it make sure it is staying lit. You can try first playing around with the cord to see if it is bad, then play around with it near the port to see if it is the port.

[Cuc Tu]

no led and wiggling things around don't bother it.

I think it is in the circuit that switches between batt./ac because it only does it after being plugged in for a while and batt. would be over full charge.

[jlreich]

no led and wiggling things around don't bother it.

I think it is in the circuit that switches between batt./ac
That's very possible. Or it could be the battery is just going bad.

One way to narrow it down is to run the system without the battery. If it shuts down then you have an issue somewhere inside the system with the power circuitry or the power adapter. Also try running on battery only, it if shuts down then you likely have an issue with the battery itself. If neither has an issue by itself then it is likely something with the charging circuitry.

I would do these experiments either by just going into the BIOS and letting it sit there, or by running a live CD. This way if you get repeated shutdowns you are not going to corrupt windows.

[Cuc Tu]

I ran with the battery for well over an hour until it was nearly drained, then I plugged in and ran for another hour without issue.

Then I shut down and removed battery and ran off AC supply for about an hour and it just shut off.

I'll look for another supply and see.

One thing is that the BIOS had a setting to allow the fan to run continuously when on AC and it was disabled. I enabled this before the test, so it did not seem to help. I really don't ever hear the fan come on other than at bootup, oh, and now when I run on AC.