The LG machine can go on but doesn't show the lock key. So it can't wash. I changed the door lock switch with a new one but still it goes on but doesn't show the door is locked.

SOURCE: Fixing broken door lock of Indesit W123X washing Machine

no easy way to open
disconnect from mains
take top off. feel down the front to where the door lock is and see if you can feel the door peg sticking thro the door interlock. force this with your fingers and with luck the door will open
if can't do this way, break handle off and lever peg with a small screwdriver
you can buy a handle kit complete. fitting this is not difficult - split the door and all will be revealed advise you make a carefull note of where springs go etc before you start stripping it down or take a few fotos if you have a digicam

SOURCE: Washing machine door lock problem

Just try to check the door latch device. Be sure that the latch is not bound or sticking in any way .This problem with a lot of machines and it almost always was the door lock latch assembly. It has a switch inside it that pauses or stops the cycle if the door is not closed properly, when this switch malfunctions then it will pause or stop the cycle repeatedly; just from the small movement of the wash cycle. The door will actually be shut all the way and the lock may be on. You must replaced this switch so it works normal again..
Just click for the spare parts site link;
http://www.repairclinic.com/SmartSearch/SmartSearch.aspx

Hope it may help you;
Regards,
VOTIT

SOURCE: Hotpoint Aquarius WF440 Washing m/c - Door Lock light

You have probably knocked of the connector or the catch (and on these it is very fragile as I have changed the catch 3 times on mine) is broken

SOURCE: door handle of washing machine broken

if clothes are still in washer? and machine has finished cycles? then handle broke so unable to open ??? your best option is to unplug/ and if necessary disconnect water supply hoses then remove the top screws from rear panel which also secure the top panel as you will observe ? then pull backwards top panel and loft off ? you now have access/visual of the door catch inside front machine look?? at the catch and you will see how it locks ? you can lever the catch gently and door opens to fit a new door catch is easy diy and not expensive if you are confident usual problem these break ? is the time delay micro switch sticks with age /moisture try dw40 and work plunger b4 you refit door back after replacing handle/catch assy

SOURCE: lg washing machine wm-1460fhd door locked wont

We have a WM-1480FHD, with the door stuck shut. It appears the door release mechanism in the actual door has broken, so when you pull the lver part, the catch is not released. You need to get a very flat knife,insert between the door and the front of the machine, right in the middle behind the release handle and push the hook towards the right side of the machine.Once open, you can check the release mechanism in the actual door. Ours is broken, so need to sort out how to repair/replace it next!