[SOLVED] PCB / Circuit error diagnosis help

[dsiee]

I have had the following board made (https://easyeda.com/editor#id=|5199a48344e54083986d89e646be21ba|0c1847fa165742ae9f65d44d6042f223|fde959f19c7c4522b1fe0bf86f31f06b) however, I must have done something dumb as it just crashes my USBasp or Arduino as ISP as soon as i plug it in. I cannot seem to work it out though. I have soldered up two boards with almost all components and another with just the ATMega328PB, C3, M, C4 and the ISP Header. It has no shorts that i can detect with the multi-meter between any two pins on the IC or between GND and VCC.

​

Any help would be greatly appreciated!

​

PDF of PCB https://www.dropbox.com/s/zh9s1qclcvhet36/PCB_v02_20180923124443.pdf?dl=0

PDF of SCH https://www.dropbox.com/s/r4ljd3bvhsktb4w/Schematic_ATMEGA328PB-Irricon-v2_irriconAIO_20180718122822.pdf?dl=0

[dsiee]

Solved

U2 which is a SPX1117 has the tab connected to GND while the tab is actually Vout (3V3) thus shorting 3v3 to GND. Diodes on the silk are incorrect too, however, i fixed that in assembly.

[mfalkvidd]

Nice work @dsiee, thanks for reporting on the solution.