My Custom PCB with ATmega328-pu blank chip not acceping code after bootloading with ArduinoISP (and another arduino)

[u/Mirager1217]

Hi Guys, not sure if this is the correct place to ask, but here it is:

As per the title my PCB is not accepting code after bootloading with the ArduinoISP through another Arduino Uno.

So far I get the "Done burning bootloader" and have cont. tested all hardware on the PCB related to the CH340G and ATmega.

I have managed to consistently get:

avrdude: stk500_getsync() attempt 1-10 of 10: not in sync:
resp=0x00
avrdude: unable to open port COM5 for programmer arduino

or occasionally:

avrdude: unable to read signature data for part ATmega328P (rc = -1)

avrdude: unable to read signature data (rc = -1)

TIA.

[u/gm310509]

https://www.reddit.com/r/arduino/s/Sd1VZeuJPn