Part Question

I need to replace a 1 amp fast recovery rectifier diode, out of a power
supply, but I'm uncertain of the numbers/letters on the blown part. Can
anyone help out?

31DF
4 7K

I'm not sure if it's a "1" after the three of a lower case letter "l"
or even an upper case letter "I".

A component shop told me I should be able to use DTE 576 as a
replacement part. But, I'm not totally convinced.

Any help would be greatly appreciated

 

[Tim Shoppa]

A component shop told me I should be able
to use DTE 576 as a replacement part.

They probably meant NTE576, and they're probably right that it'd be a
suitable replacement for that component. It's a 5Amp fast diode so it
should be good enough. It's also 400 PIV, which should be enough for
many (but not all) line-operated supplies.

It won't necessarily fix the unit, as if there is a fault elsewhere
you're likely to blow the diode again.

Tim.

 

[Tim Shoppa]

Like maybe a snubber RC not doing their job?

Maybe, but it's more likely a failed-shorted switching transistor. And
that might've been because of the snubber RC not doing its job .
Whenever you find a failed part in a switching power supply there's
usually two or three others you haven't found yet!

Tim.