The 12VDC to 120VAC inverter does not work:
1) Its timing capacitors are with their polarity backwards which causes them to blow up.
2) Its transistors have avalanche breakdown in the simple circuit which wastes a lot of power and blows up capacitors even if their polarity is correct.
3) The base current for the transistors is way too low for power.
4) The output is about 25W with a low output voltage.
the output voltage is a square-wave. Many electronic products will not work properly from a square-wave since they are designed for a sine-wave that has a much higher peak voltage.