Browning knob won't stay turned on...

try cleaning the toaster but uplugg it first, maybe there are crumbs stuck in the toaster that wont let the bread toast

Never back off the limb pocket bolts more than 3 turns or it may come apart. Check your users manual for max turn out. Always to be sure you back out each bolt equally or your timing will be off. If you think you made a mistake tighten both bolts all the way in and start over. I repair Archery equipment in northwest Indiana. The Archery Clinic

I have no experience with the deLonghi toaster but in my experience automatic toaster all work in similar ways since they went electronic - toasters were about the first to do that.

Pressing the lever down against the spring pressure also presses an internal switch that sends current to the heating element as well as to the electronics that control an electromagnet, the purpose of which is to keep the mechanism engaged until the toast is brown enough and then the current to the magnet will be cut by the browning brain and the toast pops up.

If removing any crumbs from inside by inverting it and giving it a good shake and then pressing the lever a few times fairly vigorously doesn't make it work then nothing short of surgery will make it work so returning it will be the only realistic option.

try turning it all the way on if it's a timer switch,, then rotate back, If its just a on off switch, your going to have to replace it, unfortunatly its in the UK and thats the only place I could locate it,, but heres the link for that
http://www.dualit.com/spares/01362

It could be your browning control is not working or it needs to be moved to a darker setting.

I could not find the instructions for your specific model but in order to achieve uniform browning it is recommended you wait a minimum of 30 seconds between each toasting to allow the control to automatically reset. This could be the problem if the first cycle of toasting completes correctly; you need to wait the minimum 30 seconds before starting a second cycle.

If the product is less than a year old and under certain condition Kenwood will replace.

Contact information: http://www.kenwoodworld.com/uk/Customer-Service/

Turn heat down, try covering said foods that brown too fast with some foil.

I would advise you to call Kitchenaid Customer Service. They would be able to send you a replacement timer knob at no cost. You may simply pull off the broken timer knob, and the new knob will snap in with ease.

Their toll free telephone number is 1800-541-6390.

have you cleaned the inside of the oven lately?  With the unit unplugged!

You can fix this yourself by following these instructions. Unplug your toaster before proceeding!... Clean the toaster first. Turn the toaster upside-down and shake out the crumbs. Remove and clean the bottom crumb tray. 1. Unscrew the four Phillips head screws located in the corners of the bottom base. Remove the screws completely if possible. Do this over a cloth or newspaper - that way a stuck screw won't get lost if it falls out later. 2. With the toaster right-side up, pull off the wide toast lever knob. Do not remove the round adjustment knob (it will not come off from the outside) but make a mental note of what number (1-7) is showing at the knob's adjustment mark. 3. Carefully pry up the end of the case cover with the knob on it (don't pull on the "stop" button). When the knob's plastic shaft is clear of the circuit board, gently pull off the cover. 4. On the inner part of the circuit board you will see a black plastic "cam" surrounded by two sets of electrical contacts. Rotate the cam to open the contact points if necessary. Insert a thin nail file between the points and rotate the cam to trap the file between them, then scrub back and forth several times to clean the contact points. Do this for each contact on both sides of the cam. When finished, rotate the cam clockwise so it is all the way back down to it's original position. 5. To make re-assembly easier, remove the round adjustment knob from the cover by depressing the half-round shaft flanges inside the cover with your fingernails. 6. Re-assemble the toaster by reversing steps 1 & 2. Replace the knobs, making sure that the round one is in the same position you noted earlier before you push it all the way down.