Strange effect of a level shifter between Atmega (3.3v) <=> SIM900 (2.8v)

Using Arduino General Electronics
3

I have made a mistake, it was TP1 not TP2 in this : When I put TP2 to GND with a wire, the power current increase to 0.1 A (idle 0.05 A), why ?

So I corrected my post.

Docedison:
Yes tp2 connects to the output of a ''245, If it is high you are potentially damaging the '245 by shorting tp2 to ground. If you NEED to pull PT2 down add a series resistor between the gate and TP2 470R should be within device limits

Bob

I think that TP2 is wired on the INPUT side of the level sifter, so It should be OK.