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When I start up my laptop, my keyboard sends ^[[[B all the time. This causes the BIOS to show the settings manager. When I close the BIOS manager, GRUB/Linux will start up. Suddenly the screen is filled up with the sequence ^[[[B.

Strangely enough when I press any key, the problem disappears.

Does anyone know why? Or what key sends the sequence ^[[[B ?

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If you swap keyboards, does it make a difference? – soandos Aug 24 '11 at 15:42
@soandos Not that easy with a laptop. – Daniel Beck Aug 24 '11 at 15:42
ouch, sorry, should read more carefully next time. – soandos Aug 24 '11 at 15:44
@soandos Thank you for the idea. I hope I can solve the problem without buying a new keyboard. – SecStone Aug 24 '11 at 19:22

^[[B is the Up arrow key. (It's not exactly the same as in your question, but far more likey.)

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To find out if this is a hardware or software thing, grab Linux Live CD and try booting from it (assuming you can get to it). If you still see the characters, chances are it's hardware.

I would also make sure your keyboard is clean and the key isn't stuck.

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