Nu-tec NTV2131 51cm TV

Take the cover off, the switches should be pretty easy to replace. In the several I've done, they just snap out, unplug, and then snap back in.

It sounds like the main board is malfunctioning and needs to be replaced. Depending on the age of the tv, you may just want to replace it. Please post the make and model to help us better assist you.

Thank you for using Fixya and good luck

Hey JT Tai, I appreciate your post!
The symbol at the top left hand side of your display could be child lock symbol or vent symbol. If it is the child lock you should be able to press and hold the stop/cancel button down for 3 seconds to release the child lock.

If the light is on for the vent I would seek assistance from a professional for proper diagnosis and repair to be completed on your microwave. I hope this is helpful. -Matt

see the video attached. God bless you

Error 51 doesn't exist on SCC and SCC_WE models. If you are referring to a Combi-master or Combi-master Plus (CM or CMP) then error 51 means the battery on the control board is below 1.5 volts and should be replaced. Go to your local electronics or grocery store and buy a CR2032 battery, it looks like a quarter. Open up the front control panel and replace the battery.

The door swing hinges might have come out too far try and lift up and push in at the bottom other than maybe a lock switch for when you put it on self cleaning at the top ,Don't know

When you turn on the hobs main power, press the the rear left hand element pad at the same time and the lock will come off.

press the centre minus button and the bottom right plus button at the same time it will work if not keep trying
You have to hold down the centre sensor button with the minus on and the sensor which turns on the bottom right ring immediatley after turning the hob on. It should unlock, then press the minus again
the hob switchs off
when you now switch on there will be no lock

Press and hold CANCEL/OFF button until "UNLOCK" appears on display screen.

SE error means you have a shorted membrane keypad.

With your model number I can detail your options.

Changing bulb in DeLonghi ED 8525S-SBD
This is merely an account of how I fixed mine - do this at your own risk. The oven is full of high-voltage items which include large capacitors which are not discharged when you unplug it from the mains. You can still get a life-threatening shock from the charge which is stored in these components. 
Therefore do not touch ANYTHING electrical except the bulb connectors.
1. Unplug the oven and place on a suitable surface 2. Remove the cover. This is held by five screws at the back of the of the machine. Three are along the top and are philips type and the other two are on the bottom left and bottom right corners and are star-grip. The cover must slide backwards first before coming off. 3. Find the bulb holder. It is located on the right of the oven as you look at it from the front. Turn the oven so that its right side faces you. The bulb holder is an oval black part with two electrical connections coming off it. It is about 6-7 cm long and 3 cm wide. It is mid way in the oven (from top to bottom) and a little towards the front. It is held to the oven frame with two bent metal prongs 4. Remove the electrical connectors by sliding them backwards. 5. Bend back the prongs and lift out the bulb holder. 6. The bulb in a 20W 240V oven lamp with a standard oven lamp screw-on fitting. 7. Replace the bulb. 8. Put the bulb holder back in place, bend the prongs back to secure it, re-connect the electricals. 9. Replace the cover and screws.