I connected my multimeter to positive and negative rail and set it to measure DC voltage to max 1000V.
I have not connected transformer yet. I have not winded it yet. I am connecting and examinig the circuit step by step.
How I say use light bulb in series to secure each step.
The kickback voltage start happening when I come to step to connect the transistors.
--> mark the position of the connections in a schematic.
Or upload a photo (max 100kBytes) where we can see the whole circuit and especially the connections.
at this point .... there are two 1000uF in series.
According my understanding it is impossible for "kickback" to generate voltages in the range of 1000V there.