How to properly turn on an HP ProBook laptop: 5 working methods

Laptops HP ProBook 400/600 series (models 440 G8, 450 G9, 640 G10 etc.) are known for their reliability, but even they sometimes refuse to turn on. The reasons may be different: from a dead battery to software failures. In this article we will look at all possible ways to turn on - from basic to advanced, which will help even if the laptop does not respond to the power button.

It is important to understand that the startup algorithm depends on the state of the device. For example, if the indicators are on, but the screen is black, this is one scenario, but if the laptop is completely “dead”, this is a completely different scenario. We have structured the material so that you can quickly find a solution to your situation. Let's start with the simplest and move on to more complex methods.

1. Standard activation: power button and its features

Most users include HP ProBook by pressing the power button - a round or rectangular key with a ⏻ icon located on the top panel of the keyboard (usually to the right of Delete). However, even here there are nuances that few people know about:

• 🔘 On models ProBook 430/440 G8 The power button is combined with a fingerprint sensor. Press strictly in the center to avoid false positives from the scanner.
• ⚡ If the laptop is connected to charging, hold the button for 3-5 seconds - this will reset temporary blockages (for example, after overheating).
• 🔋 On ProBook 650 G9 and newer, the power button may flash white when the battery is low. In this case, connect the original adapter and wait 10-15 minutes before turning it on.

If the laptop does not respond to a short press, try hold the button for 10–15 seconds. This will forcefully turn off the power (similar to removing the battery on older models). After this, release the button and press it again once. This “hard reset” helps in 60% of cases when the device is stuck at the BIOS level.

A critical feature of the ProBook 450 G7 and older: if the laptop was turned off through the Windows menu (not through the button), the first startup may take up to 20 seconds due to checking the TPM chip. Do not interrupt the process - wait for the logo to appear HP or a rotating indicator.

2. Power check: battery vs AC adapter

Nutritional errors are the most common reason why HP ProBook does not turn on. Let's start with diagnostics:

1. Connect the original power adapter (with a power of at least 45W for models of the 400 series and 65W for the 600 series). The use of non-original chargers may block switching on due to protection against voltage surges.
2. Check the light on the adapter: on models ProBook 640 G9 it should burn orange (charging in progress) or green (full charge). If the indicator does not light, there is a problem with the cable or power supply.
3. Disconnect the battery (if it is removable): on ProBook 445 G8 and similar models, the battery is secured with two latches. Remove it, connect the charger and try to turn on the laptop without the battery.

Symptom	Possible reason	Solution
Power light flashes white (3 times)	Battery or adapter error	Replace the charger or reset the BIOS
The laptop turns on only from the mains, without a battery	Battery wear (capacity < 20%)	Battery calibration via HP Support Assistant
The charging indicator is orange, but the laptop does not turn on	Lockout due to overheating of the power controller	Turn off the power for 30 minutes, then try again

⚠️ Attention: If, after connecting the charger, the laptop starts to warm up, but does not turn on, this is a sign of a short circuit on the motherboard. Immediately turn off the power and contact service.

For models with a non-removable battery (ProBook 430 G10 and newer) do forced reset of the power controller:

1. Turn off charging.
2. Hold the power button 30 seconds.
3. Connect the charger and try turning on the laptop.

3. Reset BIOS/UEFI: when the laptop is frozen at the firmware level

If HP ProBook turns on, but the screen remains black (or the logo appears HP no progress), the problem may be a BIOS settings failure. This is relevant after an unsuccessful firmware update or parameter changes (for example, enabling Secure Boot without OS support).

To reset the BIOS to ProBook there are two methods:

• 🔧 Hard reset (for all models):
1. Disconnect charging and remove battery (if possible).
2. Hold the power button for 15 seconds.
3. Connect the charger (without battery) and turn on the laptop. The BIOS will automatically reset to factory settings.
• 🖥️ Reset via BIOS menu (if the screen is working):
1. When turning on, hold F10to enter the BIOS.
2. Go to Security → Secure Boot Configuration and turn off Secure Boot.
3. Tab Exit → Load Setup Defaults → Save & Exit.

Disable all peripheral devices (flash drives, mouse)

Use original power adapter

Write down current BIOS settings (if you have access)

Do not interrupt the reset process -->

On models ProBook 650 G8 and later after resetting the BIOS you may need to enter administrator code. By default, this is an 8-digit combination that can be found on a sticker under the battery or in the documentation. If there is no sticker, use the universal code for HP: 31355678 (works in 80% of cases).

⚠️ Warning: Do not update the BIOS on ProBook via Windows if the laptop is running on battery power. Interrupting the process will lead to the device becoming “bricked” - restoration is only possible in a service center using a programmer.

4. Diagnostics by indicators: what do flashing lights mean?

Laptops HP ProBook equipped with a light indication system that helps determine the cause of the malfunction. Let's decipher the main signals:

Indicator	Flashing color/mode	Meaning	Action
Power (round indicator)	White, blinks 1 time	Normal operation	—No action—
Food	Orange, blinks 3 times	Battery error	Remove the battery, work from the mains
Caps Lock	Flashes 2 times white	BIOS error (damaged firmware)	BIOS reset or flashing
Food	Red, constantly on	CPU/chipset overheating	Turn off the power for 1 hour, check the cooler

On models ProBook 440 G9 and newer added diagnostic indicator next to the power connector. If it blinks green — a problem in the operating system (for example, the Windows bootloader is damaged). In this case:

1. Create a bootable USB flash drive with HP Cloud Recovery Tool.
2. When turning on, hold F9 to select a boot device.
3. Select the flash drive and follow the recovery instructions.

How to decipher Caps Lock blinking on ProBook 600 series?

On ProBook 640/650 G8/G9 indicator Caps Lock used to diagnose hardware failures:

- 1 flash: CPU error.

- 2 flashes: BIOS failure.

- 3 flashes: Memory (RAM) problem.

- 4 flashes: Graphics adapter problem.

- 5 flashes: TPM chip error.

To fix it, you need to replace the faulty component or flash the BIOS in the service.

5. Alternative ways to turn on: what to do if the button does not work

If the power button is mechanically damaged or unresponsive, there are workarounds:

• 🔌 Power on via charger:

On some models (ProBook 455 G8) connecting the original adapter automatically starts the laptop. Try disconnecting and reconnecting the charger - the device may turn on without pressing the button.

• 🖱️ Using the keyboard:

On ProBook 600 series with a docking station connected (HP Thunderbolt Dock) inclusion is possible through a combination Fn + B (if the docking station is connected to power).

• 🔧 Direct contact closure (for advanced users only!):

There are pins on the motherboard PWR_SW# (usually next to the power connector). Gently close them with a screwdriver for 1-2 seconds. Risk: Damage to the board due to incorrect connection!

For models with Touch ID (For example, ProBook 440 G10) the power button may be blocked due to a failure of the fingerprint scanner. In this case:

1. Disconnect all peripheral devices.
2. Hold the power button for 20 seconds.
3. Connect the charger and press the button once. If the scanner is faulty, the laptop will turn on bypassing it.

6. Software reasons: when Windows or firmware is to blame

If HP ProBook turns on (indicators are on, the fan is spinning), but the screen remains black or an error appears, the software is to blame. Let's consider some scenarios:

• 🖥️ Black screen after HP logo:

Reason: Windows bootloader is damaged or driver conflict. Solution:

1. При включении удерживайте F11 для запуска Recovery.
2. Выберите "Устранение неполадок → Дополнительные параметры → Восстановление при загрузке".
3. Если не помогает — выполните сброс Windows с сохранением файлов.

• 🔄 Cyclic reboot (BSOD):

Culprit: Driver update or crash TPM 2.0. Disable Secure Boot in BIOS and boot into Safe Mode (hold F8 when turned on).

• 🛡️ "BitLocker Recovery" error:

Appears after replacing the hard drive or resetting the BIOS. The recovery key can be found in your Microsoft account (at account.microsoft.com/devices/recoverykey).

On models ProBook 650 G9 with Windows 11 an error may occur INACCESSIBLE_BOOT_DEVICE after the update. Solution:

1. Boot from the Windows installation flash drive.
2. On the command line (Shift + F10) do:

bootrec /fixmbr
bootrec /fixboot
bootrec /scanos
bootrec /rebuildbcd

3. Restart your laptop.

FAQ: Frequently asked questions about turning on the HP ProBook

The laptop turns on but immediately turns off. What is the reason?

This is a common problem overheating or cooling system malfunction. On models ProBook 450 G8 and similar:

1. Turn off the power and turn the laptop over.
2. Make sure the ventilation openings are not clogged with dust.
3. If after cooling (30+ minutes) the problem remains, the thermal paste or cooler needs to be replaced.

Also check RAM: Remove the strips and clean the contacts with an eraser.

How to turn on ProBook without power button (mechanically broken)?

There are 3 options:

1. Via docking station: connect HP Thunderbolt Dock — some models turn on automatically when power is supplied to the dock.
2. Close the contacts on the board: Locate the connector on the motherboard PWR_SW# (usually signed) and carefully close the contacts with a screwdriver.
3. Use Wake-on-LAN: If the laptop was in sleep mode, you can turn it on over the network (preliminary configuration in BIOS is required).

For a permanent solution, replace the power button (repair cost ~1500–2500 rubles).

After updating the BIOS, the laptop does not turn on. What to do?

This is a critical error since the BIOS is responsible for booting. Actions:

1. Turn off charging, remove the battery (if possible), and hold the power button for 30 seconds.
2. Connect the charger and try turning on the laptop. If it doesn’t help, it’s required flashing the BIOS with a programmer (only in the service).

On models ProBook 600 series There is a hidden connector for emergency firmware (under the keyboard). But for this you need a special cable and firmware from HP.

The laptop turns on only from the mains, without a battery. How to restore battery life?

Causes and solutions:

• Battery wear: If the capacity is below 10%, replace the battery (original for ProBook 450 G9 costs ~5000–7000 rub.).
• Resetting the Battery Controller:

1. Отключите зарядку и извлеките батарею.
2. Удерживайте кнопку питания 60 секунд.
3. Подключите зарядку, вставьте батарею и включите ноутбук.

• Updating the Power Management Driver: download the latest version HP Battery Health Manager from the official website.

The error "No Bootable Device" appears on the screen. How to fix it?

The error means that the laptop does not find the boot disk. Reasons:

1. SSD disabled in BIOS: go to BIOS (F10), check the section Storage → Boot Options.
2. Windows bootloader is damaged: use HP Cloud Recovery for recovery.
3. Drive faulty: Connect the SSD to another device and test it CrystalDiskInfo.

On ProBook 650 G8 with two SSDs, check the boot priority in the BIOS - sometimes the system tries to boot from an empty disk.