Laptop only powers on with battery

[Papayoyo]

My HP 6730b has developed a fault in its power circuit.

- When turned off it charges the battery fine.
- It powers on fine when battery connected & charged.
- But it won't power with AC adapter only (with battery removed). LEDs flicker for a second, power goes to USB for a second, but no signs of laptop powering on.
- It won't charge the battery when turned on (powered by battery).

It seems to me like a power MOSFET or capacitor or fuse is blown in the power circuit.

I'm prepared to take it apart and have a go at repairing it.

I've managed to locate the circuit diagrams.

Any ideas how to diagnose and replace the damaged component(s)?

[Papayoyo]

Originally Posted by febseo

You should have to change or consult to service center dealer and you can get cheap computer hardware replacement.

Thanks
CntMicroSystems

Thanks for the spam!

Anyone can actually offer some real advice?

[Murf]

Try this:

1.Shutdown the notebook, unplug the AC Adapter, remove the battery, and then hold down the Power button for a full minute.


2. Now, plug in the AC Adapter without the battery inserted, start the notebook, open windows Control Panel, open Device Manager, expand the entry for Batteries, right click on and the Microsoft ACPI Compliant Control Method Battery and select Uninstall - do not uninstall anything else here.

3. When the uninstall is complete, shut the PC down, unplug the AC Adapter, re-insert the battery and then start the PC on just the battery. Windows will automatically reinstall the driver - leave Windows running for a few minutes. Shutdown the PC again. Plug in the AC Adapter (with the battery still inserted) and start the notebook to see if this has helped.

Note: Obviously if it will not start with just the AC Adapter, then there is something else wrong.

[Papayoyo]

Originally Posted by Murf

Try this:

1.Shutdown the notebook, unplug the AC Adapter, remove the battery, and then hold down the Power button for a full minute.


2. Now, plug in the AC Adapter without the battery inserted, start the notebook, open windows Control Panel, open Device Manager, expand the entry for Batteries, right click on and the Microsoft ACPI Compliant Control Method Battery and select Uninstall - do not uninstall anything else here.

3. When the uninstall is complete, shut the PC down, unplug the AC Adapter, re-insert the battery and then start the PC on just the battery. Windows will automatically reinstall the driver - leave Windows running for a few minutes. Shutdown the PC again. Plug in the AC Adapter (with the battery still inserted) and start the notebook to see if this has helped.

Note: Obviously if it will not start with just the AC Adapter, then there is something else wrong.

Thanks, tried to try that already but yes, it won't even boot into BIOS without a charged battery.

I'm just gonna have to be brave and rip the motherboard out and have a good look. Hopefully it's just a blown capacitor or mosfet and my soldering skills are good enough. I wonder if there might be a simple fuse blown. Do laptop motherboards have fuses? THEY SHOULD DO.