Help to identify burned components, Acbel iPower 85H, 550w

[Quaddro]

Hello..

Yesterday my friend gave me a psu, Acbel iPower 85H, 550w.
Dead one, and no 5vsb.
Then i had open the cover, and found one diode is burn. and the ic power switch bh0170a is burned too.

The diode was burned so hard, so i can't identify the mark on the diode.

I have draw the simple schematic to the ic near the burned diode, bh0170a.

I have the spare for ic bh0170a, so i need to identify the diode, to make this psu work again.

here are some photos ..
thanks in advance for any help

[stj]

Re: Help to identify burned components, Acbel iPower 85H, 550w

probably a fast rectifier like a UF4007

btw, it will have damaged the 100uf electrolytic

[Quaddro]

Re: Help to identify burned components, Acbel iPower 85H, 550w

probably a fast rectifier like a UF4007

btw, it will have damaged the 100uf electrolytic

Ok, ultra fast rectifier. thank stj.
But how about FR154 fast recovery rectifier diode?
Will it work too?
Because i have a few brand new FR154..

And this is my only one ic bh0170a left in my spare part box..

[stj]

Re: Help to identify burned components, Acbel iPower 85H, 550w

it just has to handle the voltage & current of the chip while beeing fast enough.
voltage & current is nothing,
so if FR154 can handle say 150KHz then it should work.

[Quaddro]

Re: Help to identify burned components, Acbel iPower 85H, 550w

it just has to handle the voltage & current of the chip while beeing fast enough.
voltage & current is nothing,
so if FR154 can handle say 150KHz then it should work.

Ok, thanks alot for the info, stj.

I'll try with FR154, hope this works..

[budm]

Re: Help to identify burned components, Acbel iPower 85H, 550w

That diode is for making DCV running Voltage for the SMP, that Voltage is probably also used to run other SMPS IC of the power supply that is fed through a switched Transistor when PS-ON is present, you can see the trace form the Cathode going to other places. You may have shorted loads some where, and I am surprised that the SMPS IC did not go into protection shutdown mode.
Something is drawing too much current, the Voltage DCV from AUX circuit is probably only around 20Vdc at the most and not very high current either.