Hakko FX-951 Clone: Further tests & circuit analysis

Additional info: It looks like the thermo-couple integrated in the tip is not a Type-K but a Type-N, which has a lower sensitivity.
That explains the measured sensitivity and the unlinearity/offset at 200°C and 350°C. It´s in perfect agreement with the published sensitivity when the unlinearity is not taken into account by softare.
Some more tests, comparison to original PCB, circuit analysis and ideas for simple improvements.
Related videos:

Genuine Hakko FX-951 teardown from jwrelectro:
Additional info/files from jwcelectro for the FX-951:
Schematics & Datasheets of the fake FX-951:

ATTEN AT-80D reverse-engineering + fixing the problems:

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[MrCanidi]

When you take the key card out (or just slide it a little out not removing it completely from the slot) you will see the real temperature not only the set temperature. With the key card pushed completely in you only see the set temperature and the dot is telling you when it is heating up.

[creed.]

awesome vid . have you found what op amp fits to replace the lm358 ? and what r7 resistor would be best i would like to up grade mine may be a vid on the adjustments and fitting please thank you

[pauljblo]

Did you make another video with improvements on the hakko I couldn't see anymore videos?

[GregLedet]

Roger, did you ever finish working on the Nano MCU replacement, or did you finally give up on this one?

[RoeeBloch]

Hi what is the Maximum current out of this circuit? did you test current out ?

[tablatronix]

Great project!, I wish the stands for the 951 were not so crappy looking, they look cheap

[andreiciora]

But the transformer how much power have .