Recently, I tried to get my old NXT 2.0 brick fixed.
Everything seemed to point to the clicking brick problem, but it turns out not to be the only thing, the brick was also getting hot. After disassembling it, I found that the "q27" transistor was burning up.

There is "11 2x" written on the part, but it didn't point me to anything on the internet and I couldn't find any schematic for NXT 2.0 on the web. Any ideas how to identify the part?

Or maybe anyone saw the schematic for NXT 2.0?
Would writing an email to Lego give me anything?

  • writing to lego will not help as they are no longer working on the NXT, alternatively you can buy a replacement from third-party seller like eBay. Commented Jun 14, 2020 at 17:22
  • I do not think this is something we can solve, we are not expert technicians using weird electric thingies to spot other weird electric thingies. I think you should probably buy a replacement. Commented Jun 14, 2020 at 22:21
  • 2
    @mindstormsboi Even though the subject matter of this site is not electronics, it is a valid LEGO question, and I think the tone of your comment is not very welcoming to the OP, who is asking for our help.
    – Phil B.
    Commented Jun 15, 2020 at 0:42
  • It's ok. The thing I was after the most is the schematic. If it isn't anywhere, I'm out of luck and will reverse engineer the power regulator inside. I will let you know how it goes.
    – John
    Commented Jun 15, 2020 at 6:27
  • If the getting the schematic is the main goal then perhaps we should change the title of the question. Commented Jun 22, 2020 at 15:00

3 Answers 3


The electrial schematic for the NXT is available in the LEGO "NXT Hardware Developer Kit". This can be found on the official LEGO MINDSTORMS download page near the bottom of the page in the Advanced Users – Developer Kits section.


It is likely that the main chip is dead. But if you don't have decent soldering gear then you might as well just get a new brick.


It will never hurt to contact Lego support. Customer support is busy right now so at worst you will get a no in a few days. I have had great experience with Lego support, sending me replacement pieces and replacing my NXT brick with a dead screen (common problem). You may need to provide some proof of purchase (for the NXT brick I wasn't, and I don't remember for the pieces).

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