Dell 15-5567 turns on automatically from battery

[mcplslg123]

Modelell Inspiron 15-5567
Platform:LA-D802P rev 1.0

Problem: Laptop works fine with charger and with charger+battery(both connected). However, gives trouble with battery only.

When you connect the battery(while ac power removed)-everything is fine-you can turn it on and there is display. But once you turn it on from battery and you turn it off(from bios setup/windows)-it shuts down perfectly but turns on within next 30 seconds. This doesnt happen with only ac power, and AC+batt connected together. happens only on battery alone.

01.Power switch is not the issue as i'm switching the board directly by shorting to gnd.
02.Flashed dell virgin bios(main 16mb). have not touched/flashed microchip as i fear this sio as it has bootloader.
03.No corrosion,liquid damage.
04.DC in fet and battery output fet are ok.
05.Windows issue ruled out as the problem persists even shutting from bios without hdd connected at all.

Honestly, I've never experienced this before and have no idea about the probable causes. It has internal battery and another battery is not available with me. battery health shows excellent in bios and it charges/discharges well.

Any ideas friends??

[piernov]

Re: Dell 15-5567 turns on automatically from battery

Same when putting to sleep?

[caspian]

Re: Dell 15-5567 turns on automatically from battery

I had many laptops that used to automatically start when we connect AC power or Battery for the first time or when the mainboard is out of the laptop. Then, when I reassemble the laptop and connect everything to the mainboard, the auto-start problem will be gone after a few number of starts and shut-downs.
If this is not the case, I think you have to do a real-time tracking of control signals on the mainboard.

[caspian]

Re: Dell 15-5567 turns on automatically from battery

probably an unexpected signal gets on between the battery, the SIO, and the charging IC.
For example, I have an external Fax modem connected to my desktop PC. when the PC is off, if I turn the Fax modem on, then the PC starts automatically. I mean even a signal from a modem can turn a PC on.

[mcplslg123]

Re: Dell 15-5567 turns on automatically from battery

Same when putting to sleep?

yes

[mcplslg123]

Re: Dell 15-5567 turns on automatically from battery

I had many laptops that used to automatically start when we connect AC power or Battery for the first time or when the mainboard is out of the laptop. Then, when I reassemble the laptop and connect everything to the mainboard, the auto-start problem will be gone after a few number of starts and shut-downs.
If this is not the case, I think you have to do a real-time tracking of control signals on the mainboard.

Thats wierd but will give it a a try.