It can be very frustrating when your laptop suddenly turns black and won’t start up properly. There could be several reasons why this is happening, but don’t worry – in most cases it is possible to fix it yourself without having to pay for an expensive repair.
Quick Overview of Common Causes
Here are some of the most common causes of a black screen on laptops that won’t start up:
- Battery issues – the battery may be completely dead and unable to power the laptop.
- Screen connection problems – the screen cables may have come loose.
- Motherboard failures – your laptop’s motherboard may have partially or fully failed.
- RAM issues – your RAM chips may have become loose or faulty.
- Hard drive failures – your hard drive may have crashed or become corrupted.
- Overheating – dust or fan failures may have caused the laptop to overheat.
The specific steps you need to take to troubleshoot and fix a black laptop screen will depend on what is causing the problem. Here are some steps you can try yourself before taking it in for professional repair.
Step 1: Check the Power Supply and Battery
The first thing to check with a laptop that won’t turn on is the power supply and battery. Here’s how:
- Make sure the power adapter is plugged into both the wall and laptop firmly. Unplug and plug it back in to reset the connection.
- Try plugging the adapter into a different wall outlet in case the original one is faulty.
- If you have a removable battery, take it out and put it back in to reset the contacts.
- Remove the battery entirely and try turning the laptop on just with the adapter plugged in.
- Use a voltmeter to check that the adapter is outputting the correct voltage (typically 19-20V).
- If you have a spare compatible adapter, try using that instead.
- If the battery is removable, borrow a compatible battery from someone and see if the laptop will start up with that battery.
If the laptop powers on with a spare adapter or battery, then your original power components may need replacement. If it still doesn’t turn on, the issue is likely something else.
Step 2: Drain Residual Power
Over time, residual power can build up in components and prevent a laptop from starting up properly. Try draining it:
- Unplug the battery and power adapter.
- Hold down the power button for 60 seconds to drain residual power.
- Open the case and disconnect the internal CMOS battery for 5-10 minutes.
- Reconnect the CMOS battery and put the case back on.
- Plug the power adapter back in and try turning it on.
This procedure resets the laptop’s internal power regulators. If the laptop starts up normally, then residual power buildup was likely the issue.
Step 3: Check Internal Connections
Loose or damaged cable connections inside a laptop can prevent power from reaching components. To check this:
- Carefully open up the laptop case and remove the battery.
- Visually inspect the internal cable connections to make sure nothing is loose or damaged.
- Reseat connections for the power button, screen, hard drive, etc. Unplug and plug them back in firmly.
- Pay special attention to the screen cable connector on the motherboard. Reconnect it firmly.
- Try cleaning the connections with electrical contact cleaner spray to remove corrosion.
If a cable was loose and you reseated it firmly, see if the laptop will start up normally again. Damaged cables will need replacement.
Step 4: Test Individual Components
You can narrow down the source of a problem by testing components individually:
- Remove all non-essential components – Take out the hard drive, optical drive, RAM sticks, wireless cards, etc. and try booting it up minimalistically.
- Test the memory (RAM) – If you have multiple RAM modules installed, remove one at a time and try booting with only one stick in. Test each stick individually in each RAM slot.
- Try an external display – Connect the laptop to an external monitor via HDMI or VGA to see if the screen turns on.
- Check the hard drive – Remove the hard drive and connect it externally to another computer as a secondary drive. See if you can access the files on it.
This can help you pinpoint exactly which piece of hardware is faulty if you can get the laptop to start up with only certain components installed.
Step 5: Remove Non-Essential Components
As mentioned in the previous step, removing all non-essential hardware and seeing if the laptop will start up in that minimal state can help troubleshoot the issue. Here are some specific components to try temporarily removing if the laptop won’t start up:
- RAM modules
- Hard drive
- Optical drive
- Wireless/Bluetooth cards
- Keyboard
- Discrete GPU (if present)
- External peripherals
If the laptop successfully boots up with only the essential motherboard, CPU, and screen connected, you know one of the components you removed is causing the issue. Replace or reseat them one at a time until it stops booting to find the problem hardware.
Step 6: Replace the CMOS Battery
The small CMOS battery on laptop motherboards provides power to the BIOS/UEFI firmware. If it runs down or dies, it can cause startup issues. To test this:
- Locate the CMOS battery on the motherboard, remove it, and wait 5-10 minutes.
- Reinsert the old battery or install a new CR2032 CMOS battery.
- Plug in the laptop and try turning it on.
If replacing the CMOS battery works, the old one was providing insufficient power to boot up the BIOS/UEFI. Purchase a replacement battery for a permanent fix.
Step 7: Reset BIOS/UEFI to Factory Settings
Resetting the laptop’s BIOS or UEFI firmware to factory default settings can sometimes resolve startup freezing or crashing issues caused by settings that got changed incorrectly. Here’s how to clear CMOS:
- First, remove the power cord and CMOS battery.
- Locate the “Clear CMOS” or “Reset BIOS” jumper pins on the motherboard.
- Momentarily connect the jumper or place a conductor across the two pins.
- Replace the CMOS battery and plug in the laptop.
- The laptop will power up with factory default BIOS settings.
Check your motherboard or laptop manufacturer’s instructions for the exact location of the correct pins to short for clearing CMOS. This resets BIOS settings to default and may resolve startup freezing issues.
Step 8: Update BIOS/UEFI and Chipset Drivers
Outdated BIOS/UEFI firmware or chipset drivers can sometimes cause compatibility issues that prevent a laptop from starting up. Updating them may resolve these problems:
- Download the latest BIOS/UEFI update for your laptop model from the manufacturer.
- Follow the instructions to update the firmware from a USB drive.
- Also download the latest chipset drivers from the Intel or AMD website.
- Install the chipset drivers through Windows safe mode if possible.
New BIOS versions and chipset drivers can fix compatibility bugs that may be triggering startup crashes or instability. Just make sure to follow the manufacturer’s instructions carefully when doing BIOS updates.
Step 9: Test and Replace the RAM
Faulty RAM chips or slots are a common cause of laptops not booting up properly. Here is how to troubleshoot RAM issues:
- Inspect for any signs of physical damage on the RAM chips or slots.
- Reseat RAM by removing and reinserting the modules into their slots.
- Try booting with only one RAM stick at a time to isolate failures.
- Test each stick in a different RAM slot one at a time.
- Use MemTest86+ to scan for RAM errors. Let it run 8-10 passes.
- If you see red errors, that RAM stick is defective and needs replacement.
Swapping in known good RAM chips can help determine if the issue is bad RAM. Purchase and install new compatible RAM modules if testing confirms the current chips are faulty.
Step 10: Test the Hard Drive
If the laptop powers on but won’t boot into the operating system, the hard drive may have failed. Here is how to check it:
- Listen closely for any audible clicks or grinding noises coming from the hard drive.
- Use the BIOS settings to see if the hard drive is being detected at all.
- Remove the drive and connect it externally to another computer via USB.
- Run the drive manufacturer’s diagnostic software tests on it.
- Use a program like CrystalDiskInfo to check the drive’s health (Caution – do not attempt repairs if it is a solid state drive).
If the hard drive is making unusual noises, not being detected properly, or failing tests, it likely needs to be replaced with a new drive.
Step 11: Check for Physical Damage
Carefully inspect the physical condition of components like the motherboard for any signs of damage that could cause startup failure:
- Look for damaged capacitors – bulge/leakage indicates failure.
- Inspect for burnt spots, discoloration or melted plastic.
- Check for cracked solder joints under a magnifying glass.
- Press along flex cables to see if cracks expose conductors.
- Look for physical signs of liquid spills on the boards.
Physical damage to motherboard traces, connections or components can prevent power delivery. The damaged parts would need replacement in such cases.
Step 12: Connect to an External Display
If the laptop powers on but nothing displays on the built-in screen, connect it to an external monitor or TV:
- Use a HDMI or VGA cable to connect to another display.
- Press the display toggle shortcut key (Fn + F3, F4, F5, etc.) to switch screens.
- Adjust display settings if necessary to detect the external monitor.
- See if the laptop’s display now shows up on the external screen.
If the image appears properly on the external display, the laptop’s screen or internal connections likely need repair. At least external display allows use while fixing.
Step 13: Test Overall Voltages
Use a multimeter to check the following voltage levels on the motherboard with the laptop attempting to turn on:
| Power Rail | Normal Voltage Range |
| 19V Plane | 18-20V |
| 5V Plane | 4.75-5.25V |
| 3.3V Plane | 3.135-3.465V |
| 1.05V Plane | 1.035V-1.065V |
| 1.5V Plane | 1.425-1.575V |
| CPU VCore | 0.9-1.4V |
If any rail is outside the normal range, it indicates a bad voltage regulator or connections. This would require motherboard-level repairs or replacement.
Step 14: Test the Power Button
A bad power button can prevent a laptop from turning on properly. To test it:
- Disconnect the small power button connector from the motherboard.
- Use tweezers or a screwdriver to short the two power button pins momentarily.
- See if the laptop turns on after shorting the pins.
- You can also wire a temporary pushbutton between the pins as a replacement power button.
If shorting the pins turns it on, the actual power button is likely defective and needs replacing. This is an inexpensive fix.
Step 15: Try Disconnecting the Webcam
In some laptop models, a faulty integrated webcam can actually prevent booting. To check this:
- Carefully disconnect the thin webcam cable from the motherboard.
- Try powering on the laptop without the webcam connected.
If disconnecting the webcam allows the laptop to start up normally, the webcam circuitry is likely faulty. A motherboard repair or replacement would be needed in that case.
Step 16: Attempt BGA Reflow
If there are no visible signs of physical damage to the motherboard but it still won’t start up, a solder connection underneath large BGA chips may have cracked from thermal stress. Reflowing the solder can help:
- Remove the motherboard from the laptop case.
- Preheat your oven to 385°F (195°C).
- Place the motherboard in the oven for 7-10 minutes to heat all the solder points.
- Remove it once reflowed and allow it to cool down gradually.
- Clean any flux residue with high percentage isopropyl alcohol.
- Reassemble the laptop and test.
The controlled heat helps reflow cracked solder joints. However, take care not to overheat the board during this process. Reflowing provides a chance to revive it without replacements if done carefully.
Conclusion
Troubleshooting a black laptop screen that won’t start properly involves methodically verifying all key components and connections. Begin with the battery and adapter, then move on to connections, individual hardware, display, voltages, etc. Most issues can be pinpointed through elimination and substitution testing of components.
Refrain from turning on a laptop that isn’t starting up properly for extended periods, as this can worsen damage. Carefully inspect boards for physical damage as well. Obtain manufacturer warranty repairs if available. With persistence and care, you can determine the underlying problem yourself and get your laptop functioning again.