Hi
What is the purpose of the D8 in this circuit.
Because if the C34 is there for the blanking time, then after the first gate pulse, C34 will be charged and there is no way to discharge it other than the reset signal.
If there is no reset signal, this capacitor voltage will reach up to 5.1 V and trigger the comparator.
In order to handle that, there should be a reset pulse just after the gate pulse.
This circuit seems to be incomplete.
Regards
Damith