Reddit mentions of Ewigkeit 12V 40W Cartridge Heater 620 Ceramic and NTC Thermistor 100K 3950 for 3D Printer(Pack of 10pcs)

This is the correct answer. Here is an example

THIS.

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With the thermistor broken, the software doesn't know how hot the element is. Thankfully, the way it broke it seems to think it's too hot, or it detected something is wrong and protected itself. Without a working thermistor, however, you run the risk of thermal runaway and flames/fire. DON'T RUN IT until you replace it. They're thankfully pretty cheap to get replacement elements and thermistors. I got a pack of 5 I think for around $10 a while back.

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EDIT - I got 10 for $12. Amazon - https://www.amazon.com/gp/product/B073TVBJVY/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

These are what I got for my Anet A8

Spare heaters and thermistors:
https://www.amazon.com/gp/aw/d/B073TVBJVY/ref=ox_sc_saved_image_3?smid=ABJP334RWT1YX&psc=1

Mosfet:
https://www.amazon.com/Mosfet-MACTISICAL-Printer-Expansion-Current/dp/B077GPZZS6/ref=mp_s_a_1_15?ie=UTF8&qid=1537224262&sr=8-15&pi=AC_SX236_SY340_FMwebp_QL65&keywords=mosfet&dpPl=1&dpID=51AE32Zmt8L&ref=plSrch

If you bought one of thos $10 clones I think it would be better just buying the cables to your regular direct drive extruder that came with the printer, I bought one these thermistors and I also bought this heater cartridge. There is also this one that comes with 5 thermistors and 5 12v heater cartridges for $12.

It's possible that you forgot to switch the jumper back from USB to VREG. That would explain why the printer is only turning on the lcd and thermistor when plugin in the usb cable.