Other Parts Discussed in Thread: PMP10397
Tool/software:
Hello there,
We have used the reference design PMP10397 as it is except the transformer is changed to below specs.
Vin min=300V DC
Vin max=650 DC
Vout 15V / 0.2 A at both the output (in the reference design Input 1= 15V Input 2= 5V)
Aux Voltage = 15V
Transformer Details
Core EE20
Primary Inductance 2.5mH
Primary Turns 68
Secondary Turns 13
Secondary Turns 13
Aux Turns 13
We are now observing a triangular waveform at the VDD which goes to 21.4volts and then drops to 7 Volts approx.
There is no voltage at pin 6 i.e vs.
We also monitoring VDRV and that to is 0V.
Pls suggest troubleshooting methods or let know where we are wrong.
Additional info:- R14 is changed to 3.9K 
Also tried removing R12 and connect 21V to VDD with respect to C10 externally. still there was no pulse at VDRV or CS pin
