My Breville Ikon 4 slice toaster only works if I manually press the lifter handle all the way down and hold it there

If your power-socket is off, it won't. (I've done it several times, foolishly cursing the toaster). :rolleyes:
Otherwise unplug from wall, remove covers, check by pressing base down with a pen etc. On most auto-eject toasters, a powerful electromagnetic solenoid (electric magnet) holds the base (slice carriage) down while cool and warming up. When preset temperature is reached, solenoid is de-energized, releasing its magnetic hold on the base, allowing springs to pop bread up.
If you (or friend) has a tester and expertise, check solenoid (small coil) for resistance. If OK, (not open circuit), problem is in control circuitry.

I just fixed my Breville CT75XL Ikon 4-Slice toaster which was stuck in the on-down position. Wife said it heated up the whole kitchen and finally unplugged it. There are tamper proof screws as well as needle nose pliers needed to disassemble what appears to be a unit that is not intended to take apart or service. All I did was release the mechanism that holds and powers on the device then scrape the metal contacts with an emery board. Unit works but this buys me time to find a replacement. It won't be another 170 dollar disposable Breville made in China that's for sure. Only got 3 years 4 months use, family of 2, which is pathetic.

The fact that pressing down the lever fails, means the toaster contact will not function and can not be repaired. Since a two slice toaster is only $15 at Target, why bother fixing a toaster?

The latching relay is either faulty, or the timer module has faulted. That usually happens when the Toaster has a "Fault" on it. I suspect that the Timer has faulted. Toasters really aren't usually fixed, but if you have a handy appliance repair shop why not get a quote, for a repair, or replacement.

remove from the electricity supply
remove crumb tray,
remove bottom 4 os 6 screws.
at the bottom of the toaster there is what liooks like a flat fish hook that engages with the handle when you push the handle down to start toasting. clean around this and try to get it to engage when you push the handle down, it wont stay down unless the electricity is connected but dont plug it in as you will probably kill your self!!
put it back together abd try it
if it does not work 4 slice toaster from Tesco £9.99

The Breville BTA840XL Die-Cast 4-slice Smart Toaster is grounded and has 3 prongs.
I hope this helps.

Hi, most new toaster have a selenoid that hold down the handle while toasting then release when done so a spring bring the toast up. Possible problem with the selenoid, the electronic circuit that controls it or the plate that the selenoid holds. When you lower the handle you close the contacts of the AC line inside the toaster so if the handle is raised there is no power.

http://www.scribd.com/doc/20862186/Breville-BTA840XL-Manual

hi sounds like the problem is the holding down mechanizem clean the toaster well find that spring which caches the lever down you can find it on the external lever side pretty small and simple thing when you push down the external lever the spring kick a little lever which holds the slide in place for heatup only when you will hear a "click" then you'll know its in place and then the electric cicuit will be close and engage the coils to heatup good luck