Why does my Compaq CQ57 only show the charging light and not power on?

Firstly, it might be worth checking the internal hardware connections, as a loose or disconnected component can prevent your laptop from powering on despite showing a charging light. Here are the steps to follow:

1. Disconnect all power sources: Unplug the charger and remove the battery.
2. Hold the Power Button: Press and hold the power button for about 30 seconds to discharge any residual power.
3. Re-seat RAM and Hard Drive: Open the back cover and carefully re-seat the RAM and hard drive.
4. Check the Power Jack: Ensure that the power jack connecting the charger to the motherboard is intact and undamaged.
5. Reconnect and Test: Reassemble the laptop, reinsert the battery, connect the charger, and try to turn it on again.

If these steps don’t fix the issue or if you’re uncomfortable performing them, consider seeking professional assistance.

It’s possible that a defective power button is causing your issue. Power buttons can wear out or stick over time. Here’s what to try:

1. Press Repeatedly: Tap the power button several times to ensure it’s not stuck.
2. Disassembly: If comfortable, disassemble the casing and inspect the power button mechanism to ensure no debris is blocking it.
3. Replace if Necessary: If the power button appears damaged, it may require replacement.

A malfunctioning power button can prevent your laptop from coming to life even if it’s receiving power.

Your Compaq CQ57 showing only the charging light could mean there’s a power supply issue. This commonly occurs if the charger or its cable is faulty. You can perform these checks:

1. Inspect the Charger: Look for any visible damage such as bends or frays.
2. Use an Alternative Charger: Test with another compatible laptop charger if available.
3. Observe the Indicator Lights: If the laptop powers on with the alternative charger, the original charger is likely faulty.

Should a different charger also fail to power your device, it could indicate internal power component problems within the laptop.

The motherboard may be at fault if no other solutions work. Here’s what you can do:

1. Visual Inspection: Open the laptop and check the motherboard for visible damage, burning marks, or blown capacitors.
2. Professional Diagnosis: If you see damage or suspect the motherboard is the problem, having a professional technician check it is advisable.

Motherboard issues are complex and typically require expert diagnosis and repair.

The problem could be related to BIOS corruption. Resetting the BIOS can sometimes resolve power issues:

1. Turn Off and Unplug: Ensure the laptop is off and disconnected from any power source.
2. Access BIOS Battery: Remove the laptop’s back panel to locate the BIOS battery.
3. Remove BIOS Battery: Take out the small coin-cell battery for about 5 minutes, then reinstall it.
4. Reassemble: Close the back panel, reconnect the power, and test the laptop.

This action resets the BIOS settings to default and could help the laptop regain its functionality.

Sometimes, leaving the battery in can cause issues. Here’s a quick method you can try:

1. Disconnect the Power Supply: Unplug the charger from the laptop.
2. Remove the Battery: Take out the laptop battery.
3. Hold the Power Button: Keep the power button pressed for around 60 seconds.
4. Reconnect Power Supply: Plug the charger back in without the battery and try to power on the laptop.

This process can sometimes reset the mainboard and resolve startup problems.