Cannot enter BIOS due to broken screen

Lately my laptop (HP g42 247sb) screen is damaged, so I hook it up with an external monitor (LG something) and it works fine now.

The only annoying thing is I cannot navigate the BIOS menu for some tweaking because the BIOS not shown on the external monitor, instead, it only shown on the broken laptop screen, and it only output to my external monitor when Windows/OS is logged-on.

So, is there anyway I can force output during BIOS/BOOT/POST to my external monitor?

Things I have done and didn't work:

Set my LG monitor as primary display on both window properties and Intel Graphics panel
Enter the BIOS (F10 key) and press the Fn+F4 key (change display output).
Disable and uninstall my internal screen (broken laptop screen) using device manager and restart, but Windows (BIOS?) install it back on log-on.
Closed lid/Magnet on sensor.

gamer

Posted 2012-09-19T08:39:02.440

Reputation: 141

5If you can find someone with an identical machine, then you can do a blind walk through: Both people do the same thing on both laptops, the one with the working screen guiding the other. – ctrl-alt-delor – 2012-09-19T08:49:16.773

In addition to what richard said. Some BIOS allow do deactivate the internal Screen. If you are able to achieve that blindly it could be working after a reboot. – Langhard – 2012-09-19T09:02:55.980

Thank you for the input, but is there any other way than that because finding one with identical machine is quite hard, maybe a bios map? – gamer – 2012-09-19T09:17:57.820

It sounds like its time to replace te laptop and/or send it in for repairs. – Ramhound – 2012-09-19T11:36:45.187

Have you tried contacting the laptop tech support? It'll be a PITA but they might have some solution for you. Can you get the BIOS information (version no. etc) then possibly find more information about the BIOS, you might find information on external displays. Otherwise from all the other answers I see, probably just get the screen repaired? ... – KDecker – 2013-07-10T21:30:58.850

You don’t need another laptop to do a blind walk, just check the manual to see what the BIOS options are like, then you can take notes about positions and locations. (Incidentally, several years ago, my monitor died around Christmas and I ended up using my dot-matrix printer as a monitor to do a few things like copying files and such until I could find a replacement.) – Synetech – 2013-09-11T14:51:16.947

Answers

Please try to close the lid right after you press the start button. This works on my HP 6730b here, i can see the BIOS then.

Langhard

Posted 2012-09-19T08:39:02.440

Reputation: 560

This works on my Acer Aspire E 15 too! Thank you. I shared your solution, among many others I tried, here: http://unix.stackexchange.com/a/312326/106621

– Antonio Vinicius Menezes Medei – 2016-09-26T06:16:24.443

Closing the lid also worked for me on a 4540s, thanks. – speedyrazor – 2017-02-06T11:19:46.340

It didn't work,look like the bios(mobo?) won't even send output to vga during start-up/memory test, but thank you for your input. – gamer – 2012-09-19T09:54:12.253

This seems weird to me. Your notebook should output your BIOS to the external screen... Do you have another screen to test? Maybe its an issue with unsupported screen resolution / framerate on the LG Monitor during the bootup process..? – Langhard – 2012-09-20T08:52:02.517

I had the same problem. I took the bezel off my screen and disconnected the laptops monitor. This forces the computer to use the external monitor and shows the bios menus.

Dave

Posted 2012-09-19T08:39:02.440

Reputation: 11

This was the only thing that worked for me (though I disconnected the cable at the main board end). I dunno what happened as before I could use Win-P to "project" to external monitor and F10 did similar, but rebooted and nothing I tired could switch to external screen. – ensignr – 2018-11-15T09:17:08.903

A closed lid should force the output to the external monitor.

Most laptops detect a closed lid with a magnet and a sensor. There is a small magnet probably somewhere on the top edge of the screen, and a sensor in the area of the body of the laptop that it would be near when closed. You can use a small refrigerator magnet placed on the sensor to trick the laptop into thinking it's always closed, while still having access to keyboard and buttons.

You can find the location of the magnet by either taking off the plastic cover on your screen, looking for disassembled pics online, or just moving a magnet over the outer edge where it likely is.

DaleSwanson

Posted 2012-09-19T08:39:02.440

Reputation: 318

Didn't work, I press the start button and quickly closed the lid... even entered the bios(F10) tap some key to verify I'm in BIOS (by the beeping sound it made,I think I'm in BIOS) later I press the start button again to logon into windows and comment your answer. – gamer – 2012-09-19T09:52:31.303

It may not work if you close the lid while already in the BIOS. Try finding the sensor location while you are in windows, that way you can have it think it's closed when it's turned on. – DaleSwanson – 2012-09-19T09:54:33.690

Okay,I will try to find the sensor location now. Thank you for the quick reply. – gamer – 2012-09-19T09:57:14.900

also: at some notebooks usb keyboards work at boot time to enter bios – Langhard – 2012-09-19T09:59:10.753

1I found the sensor and place a magnet on it(the internal monitor goes off) then I restart but nothing happen, the external monitor just come up at windows logon. – gamer – 2012-09-19T10:20:27.723

According to page 38 of the manual you can switch screen output between the display devices with FnF4

I expect this also works for the output before POST has completed.

screenshit of page 38 of the manual. Relevant part marked.

Hennes

Posted 2012-09-19T08:39:02.440

Reputation: 60 739

1This is promising, assuming that the key works during the BIOS phase and is not limited to Windows (the backlight key probably works at a hardware level, but some of them may work in conjunction with a hotkey program in Windows). – Synetech – 2013-09-11T14:54:27.850

I had a this problem with a 2011 ASUS A53SV laptop which has a broken screen. The laptop was being used like a desktop with an external monitor. It had an old hard drive, and I wanted to upgrade it to an SSD.

Things that did NOT work initially:

disconnecting the display cable from the motherboard to try to force the other screen to be used
closing the laptop lid and attempting to spam F2 to get into the BIOS
attempting to navigate the BIOS blind (gave up)
pressing F8, the ASUS laptop's function button to switch displays
trying both HDMI and VGA cables

Might be forgetting some, but basically, the laptop absolutely did not want to show the BIOS on the external screen until the last option in this comment, resetting the "CR2032" battery, was done.

After taking the battery out and putting it back in, I followed this by doing the following: got Ubuntu on a DVD and took the hard drive out so only Ubuntu would boot from the DVD drive (afterwards I found out that the BIOS didn't allow booting from USB), then tried pressing F8 to switch display in an HDMI and then DVI connection. Only the DVI-to- monitor connection worked for this laptop, but it was relieving to see the BIOS on the screen for the first time after spamming F2. It may be notable that the laptop motherboard was connected to the broken screen via display cable when this occurred.

With access to the BIOS, I changed the boot priority to DVD reader first.

Finally, I cloned the OS, Windows 7, from the old hard drive onto the new SSD and put in the new SSD. After putting in the SSD, W7 was bootable right from the start, and I was able to reinstall W7 via DVD.

I think the most important part was resetting the CMOS battery and using Ubuntu and DVI cable for this problem with my specific laptop. Hope this helps others with laptops that have broken screens.

edit: I'm not a hardware repair expert and am not sure what exactly helped the BIOS appear in the end, but I'll try to distill out what I think are the important parts

reset CMOS battery
After that, try every port your laptop has for the monitor including the DVI, which worked for mine's.
Try an ubuntu boot disk and pressing the laptop specific function button to switch screens if that doens't work.

These were the most important, I think. If there are any specific suggestions for clarifications I'm open to them.

slowstrafe

Posted 2012-09-19T08:39:02.440

Reputation: 11

I'm not sure your answer actually describes a valid process for accessing the BIOS on a second screen. – Burgi – 2019-05-29T08:11:51.557