Greetings David. I have just looked at the schematic and I don't think the shorted D401 would have caused IC401 to fail. But I can't be 100% sure about that.
Do you still have the horizontal white line across the middle of the screen?
Do you have around 27v at pins 8 and 13 of IC401
Below are the voltages on the schematic for IC401.
PIN Voltage
1 12v
2 7.3v
3 0v
4 6.1v
5 0v
6 5.9v
7 5.8v
8 27.2
9 2.3v
10 n.c.
11 0v
12 11.2v
13 27.7v
I have a FS-6390 on the bench at the moment. This one went out with a bang. A piece of IC601 (STRS6708) blew out of the chip, and several other parts failed nearby.
Just a little helpful advice. If you have more to add about a previous posting, continue the thread that has already been started.
Russell