iFixit - Answers With Device "HP ProBook 400 Series"

HP ProBook 450 G2: HP Probook 450 G2 continuous light power and caps lock

Sat, 20 Sep 2025 07:07:20 -0700

Hi help

Laptop not switching on

Blank screen and continuous glow of Power button and Caps lock (no blinking sequence) when connected to a/c

What i have tried with no success

Remove battery and connect a/c
Reseat RAM
Remove power source and press power button for 20 seconds

regards

heres what its showing

⟐ Answered September 20, 2025 at 7:07 MST

HP ProBook 450 G4: Laptop will not power on

Wed, 15 Mar 2023 12:00:59 -0700

When I plug in my laptop in the power button and the caps lock button light up for a second or 2 then go out. Then the power button and the wifi and the mute button come on for a second or 2 then go out. This happens twice then the laptop becomes unresponsive. I have replaced the power supply but it still acts the same. I have tried the 30 second power button reset and no luck. Any ideas on what to do next?

⟐ Answered March 15, 2023 at 12:00 MST

HP ProBook 455 G4: screen does not turn on

Wed, 23 Oct 2024 08:51:29 -0700

My screen reduces to turn on when I press the power button but when I insert the charger, the light blinks, indicating that's it's charging but the screen does not turn on .

⟐ Commented October 23, 2024 at 8:51 MST

HP ProBook 450 G1: My screen is glitching

Sat, 24 Aug 2024 06:01:33 -0700

Screen keeps glitching after cable repair

⟐ Answered August 24, 2024 at 6:01 MST

HP ProBook 450 G4: Why my pc automatically entering bios mode, when turning it on

Wed, 10 Jul 2024 23:02:50 -0700

My pc entering bios setup when turning it on

⟐ Commented July 10, 2024 at 23:02 MST

HP ProBook 450 G5: Won't turn on or charge.

Thu, 12 Mar 2026 13:26:03 -0700

My laptop won't turn on or charge. No indicator light. Checked the cable and used another known working cable and still nothing. Does anyone know what the issue is?

⟐ Commented March 12, 2026 at 13:26 MST

HP ProBook 430 G4: My screen just wont turn on but the system does (please help )

Mon, 23 Jun 2025 04:48:42 -0700

My system goes on and off before the screen just stops working but the system do turn on, not the screen

⟐ Answered June 23, 2025 at 4:48 MST

HP ProBook 440 G3: Laptop will not power on; blinking caps lock and num lock with beep

Wed, 11 Sep 2024 20:31:53 -0700

I have a HP Probook 440 G3 that refused to boot after a failed update. It started emitting the num lock LED continuously a week before this incident.

On pressing power, it doesn’t boot but caps lock and num lock blink with 2 long beeps and 2 short beeps, then the sequence continues endlessly without the beeps heard. I have accessed the support on the HP official website to attempt restoring the BIOS but it is not helpful.

Please anyone with similar experience and how did you solve yours?

Grateful for your inputs.

⟐ Answered September 11, 2024 at 20:31 MST

HP ProBook 450 G5: POST Error hp The system has detected that a cooling fan is not oper

Mon, 23 Oct 2023 08:17:39 -0700

POST Error

The system has detected that a cooling fan is not operating correctly.

Continued operation is not recommended and may cause unpredictable behavior that could result in random shutdown, data loss or possible system damage. The system will shut down in 15 seconds. To prevent shutdown and continue operation, press the enter key now.

System Fan (90B)

For more information, please visit: www.hp.com/go/techcenter/startup

⟐ Commented October 23, 2023 at 8:17 MST

HP ProBook 430 G1: Keyboard lights activation on my Laptop

Tue, 20 Aug 2024 05:58:01 -0700

My HP Laptop keyboard lights AMD PRO A6-8500B R5, 6 Compute Cores 2C+4G 1.60 GHz have not been working for some time and how do I activate them again.

⟐ Answered August 20, 2024 at 5:58 MST

HP ProBook 430 G2: Why power button and caps lock flashes once then turns off?

Sun, 07 Jul 2024 12:56:29 -0700

Good day, i have Hp Probook 430 G2 laptop. When i plug it in charging LED indicator lits but when i start it up the power and caps lock LEDs blink once and shuts down immediately together with charging LED indicator and the charging LED indicator turns on again. Already tried hard resetting it by disconnecting the battery and the charger and pressing the power button for couple of minutes. I tried different charger, recovery of BIOS using bootable flash disk but not responding also tried replacing and cleaning the RAM. What could be the possible problem? Thanks

⟐ Answered July 07, 2024 at 12:56 MST

HP ProBook 450 G5: Replacement battery for HP ProBook 450 G5

Mon, 06 Dec 2021 11:26:22 -0700

What replacement battery do I need for the HP ProBook 450 G5?

⟐ Answer accepted December 06, 2021 at 11:26 MST

HP ProBook 440 G5: The Battery is not charging.

Thu, 24 Nov 2022 09:41:57 -0700

The battery doesn't charge does it mean it needs to be replaced?

⟐ Commented November 24, 2022 at 9:41 MST

HP ProBook 430 G5: Why is my computer doesn't turn on

Thu, 15 Jan 2026 10:00:41 -0700

When i push the button to run the computer, the led of the start button turns on and the fun starts, but the nothing happens, the computer never opened

⟐ Commented January 15, 2026 at 10:00 MST

HP ProBook 450 G6: Laptop is,not turning even the power light is not on

Tue, 05 Aug 2025 02:10:45 -0700

Laptop is,not turning even the power light is not on

⟐ Answer accepted August 05, 2025 at 2:10 MST

HP ProBook 450 G1: How to replace the hard drive?

Sat, 19 Jul 2025 09:45:43 -0700

I wanted to play on my laptop, but the laptop says bootdevice not found error. I found a solution, but I don't know how to do this.

⟐ Answered July 19, 2025 at 9:45 MST

HP ProBook 450 G7: My display screen needs replaced

Wed, 16 Apr 2025 07:16:34 -0700

I have been advised to get a screen replacement kit, do you sell them?

⟐ Answer accepted April 16, 2025 at 7:16 MST

HP ProBook 430 G2: Why my laptop is not turning on

Fri, 31 Jan 2025 11:23:40 -0700

It is not turning on

⟐ Commented January 31, 2025 at 11:23 MST

HP ProBook 450 G2: I can't access my primary partition.

Wed, 18 Aug 2021 19:41:20 -0700

I had an “UNMOUNTABLE BOOT VOLUME” blue screen recently. How do I fix it without losing my files on the primary drive? I've partitioned my hard drive into two.

⟐ Answered August 18, 2021 at 19:41 MST

HP ProBook 430 G8: Unknown SMD component, now melted on motherboard

Thu, 26 Feb 2026 07:24:10 -0700

Hi,

I am trying to identify a component on my HP Probook 430 G8 laptop Motherboard. I accidentally shorted the battery to this component.

Motherboard :

Model X8P

Year 2020

DA0X8PMB8F0 Rev: F

See photos of the component. I have lifted a trace when cleaning the area, but I believe it is fixable. I bought a 2nd laptop to try and help me get the first one working. I de-soldered what what looks to be the same component from the donor laptop.

The component is an 0603 from measuring 1.6mm between the solder tabs.

I used my DER EE DE-5000 LCR meter and get:

0.5 millihenry

0.010 milliohms

0.9 to 1.1 nanofarads

I am not sure what to order. It doesn't look like a capacitor, the resistance seems to low to be a resistor, and I can't find 0.5 millihenry inductors..... can you please help me order the correct part?

Broken laptop (Below)

(The orange led at the charge port fades in and out as orange)

Donor board whose part I measured. (Below)

I have now MAYBE identified the mosfet that is connected to the component.

Final repair

⟐ Commented February 26, 2026 at 7:24 MST