DeLonghi EC680.Surface mount diode identification help pls

[Nevillet]

Hi All,

I'm trying to repair a DeLonghi EC680 coffee machine. There is a single PCB incorporating power supply and control circuitry.

There is a shorted surface mount diode D2). Can anyone give me a pointer as to what type it is and also which end is A/K?

Are there any common through-hole diodes I can substitute?
(I think a 1N4007 would fit)

Many thanks.

[diif]

Re: Surface mount diode identification help pls

Are there no marking on the diode to indicate what it is?
The line/band indicates the cathode.

[Nevillet]

Re: DeLonghi EC680.Surface mount diode identification help pls

There is a grey band which is closer to one end than the other and my assumption that thats the K end. Helpfully there are no markings on the PCB.

[lotas]

Re: DeLonghi EC680.Surface mount diode identification help pls

With the strip, this is the cathode, it should go to the positive terminal of the capacitor, you can safely put 1N4007.

[Nevillet]

Re: DeLonghi EC680.Surface mount diode identification help pls

That's fixed it. Many thanks all.

[stj]

Re: DeLonghi EC680.Surface mount diode identification help pls

no.

thats a switching psu - the frequency is too high for 1n4007 - it will fail
you need a UF4007

[Nevillet]

Re: DeLonghi EC680.Surface mount diode identification help pls

Many thanks. I have a UF5402 in stock, will that work?

[stj]

Re: DeLonghi EC680.Surface mount diode identification help pls

200v 3a
it will work but isnt it a bit big?

[Nevillet]

Re: DeLonghi EC680.Surface mount diode identification help pls

It sure is a fat diode. I can mount it off the PCB and extend the leads with thin wires. Not pretty I know... What kind of current would you expect will run through it?

BTW:
I've ordered some UF4007's so my suggestion above more theoretical than anything else.

[lotas]

Re: DeLonghi EC680.Surface mount diode identification help pls

https://www.gmelectronic.com/diode-1n4007-smd

[Nevillet]

Re: DeLonghi EC680.Surface mount diode identification help pls

Hi Lotas, That SM device looks very like the shorted one.

[redwire]

Re: DeLonghi EC680.Surface mount diode identification help pls

D2 looks like part of the mains input, it's conected to 100R power resistor R5 to Line. So I would say a low speed 1N4007 is fine. Odd it's a single MELF package but the others are through-hole and fast-recovery needed for them.

[stj]

Re: DeLonghi EC680.Surface mount diode identification help pls

it's across the buck coil - thats probably why it died