Thermistor broken

ok,
when a print comes unstuck from the bed and starts wandering around attached to the print head then it's not sticking to the bed properly, (yay for captain obvious here!)

to increase the ability to stick to the bed you can try,
make sure that the bed height is correct,
Make sure that the bed is level. (level to the machine not level to the earth)
cleaning the kapton tape to ensure that there is no grease on it.
replacing the kapton tape
using hair spray to increase stick
printing a skirt or a brim so that there is more area in contact with the tape and more area to stick.

when you say you had to unmounted the extruder, I assume it was clogged and you needed to take the machine apart to fix it?

any ideas how you broke the thermistor? is it just a broken wire? or you broke it like you crushed t between the nozzle and the heater? broken wires could be soldered together. (or even just twisted together?

there are some basic instructions on solidoodles site about levelling the machine etc but on the whole the documentation is pretty poor... solidoodle do have instructional videos they aren't on you tube though they are somewhere else, (I've forgotten where and they don't link to them in an obvious way).

the extruder gets blocked for a number of reasons.
if you leave the heater on whilst not printing  you can burn plastic or denature it in some way so as to cause it to not melt properly and then not be able to extrude properly.
some people have found that plastic filament from some suppliers is just bad an contains rubbish stuff that's not even plastic in some stories.

the quickest way to fix it is to try poking a really thin wire (high E guitar string) through the nozzle from underneath.
as you may realise this just pokes whatever can't come out back into the machine ready to annoy you another day.

when the machine is hot, you can hold the black (peek) part of the nozzle with some pipe grips and undo the nozzle part on the end, (in fact this is easier when hot than separating them afterwards!!).

so the simple don't need to take you machine appart way of getting the nozzle off is...

Remove the thermistor from the nozzle (but leave it plugged in)
lower the Z platform so you can get your hands in.
turn the heater on,
wait for the heater to be hot. (wait about 2 minutes and turn it off, the feed back from the thermistor is useless since this will just be hanging in the air now!)
make sure the heater is off.
hold the barrel still by holding the peek (less chance of crushing the barrel)
undo the nozzle.

for part 4...

I believe that somewhere on these forums there is a part number.
or someone may know from what component value table is being used in the firmware what part number this relates to...

or you could try asking solidoodle directly.

(though whenever people have asked directly before they are told that it's a company secret.
-despite the fact that basically every part of the printer is based on GPL designs and in copying these designs solidoodle must have read the license and surely must realise that they must release their modified designs under the gpl license also!
(it's not a choice it's a requirement of the license).

Even if solidoodle didn't release the design, (and if they've never modified it, they wouldn't have to) they could at lease let us know what design they copied so that we could know the part numbers... (unless this is the company secret)!