Identify this Component

[Raj3]

Good morning sir 

Pls identify the component.i don't understand 

[Peter BENSCH]

It's the obsolete fast recovery diode SMBYT03-400 in package SMC:

• VRRM=400V
• IFav=3A
• IR<10µA @25°C, <600µA @100°C
• trr<25ns

You could consider the STTH3R04S as a replacement.

Regards
/Peter