Super User is a question and answer site for computer enthusiasts and power users. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

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:

  1. Set my LG monitor as primary display on both window properties and Intel Graphics panel

  2. Enter the BIOS (F10 key) and press the Fn+F4 key (change display output).

  3. Disable and uninstall my internal screen (broken laptop screen) using device manager and restart, but Windows (BIOS?) install it back on log-on.

  4. Closed lid/Magnet on sensor.

share|improve this question
If 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. – richard Sep 19 '12 at 8:49
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 Sep 19 '12 at 9:02
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 Sep 19 '12 at 9:17
It sounds like its time to replace te laptop and/or send it in for repairs. – Ramhound Sep 19 '12 at 11:36
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 Jul 10 '13 at 21:30

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.

share|improve this answer
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 Sep 19 '12 at 9:54
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 Sep 20 '12 at 8:52

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.

share|improve this answer
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 Sep 19 '12 at 9:52
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 Sep 19 '12 at 9:54
Okay,I will try to find the sensor location now. Thank you for the quick reply. – gamer Sep 19 '12 at 9:57
also: at some notebooks usb keyboards work at boot time to enter bios – Langhard Sep 19 '12 at 9:59
I 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 Sep 19 '12 at 10:20

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.

share|improve this answer
This 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 Sep 11 '13 at 14:54

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .