A bad diode! What the heck?

[Logistics]

So I'm holding an MSI K7T266 Pro2 board... Paps says it won't come up. His system recently took a dive due to bad caps, then he hooks up some other system he has and it's having problems so I look, bad caps as well. Then he tried to use some other hardware he has, this board, but he gets nowhere. I look all over, it has some Teapo's, some G-Luxon's and some Rubycon MBZ's next to the CPU. Wow! Next to the DIMM slots, however there is a bad diode. Vut de heck? It's split in two and charred! I can easily replace it, but can I find something like this locally, perhaps? It's marked SS12, which comes up as a Vishay diode on the net.

BTW, what could cause something like this?

[davmax]

Re: A bad diode! What the heck?

You have a wide choice from local parts suppliers. In the same construction anything from SS12 to SS100. A diode with axial lead format 1N5817 to 1N5819. The SS14 is available at my local electronics parts so you should not have too much trouble.

[Logistics]

Re: A bad diode! What the heck?

Does it have to be this same type of diode? I believe I have some plain 5819's around from an old Dreamcast VGA Box project. That motherboard board also has some SMT but non-chip type diodes on it, but why did they decide to use a chip type in this particular spot? Does it need to have the chip type or can I just use these little axial babies in it's place?

[Rainbow]

Re: A bad diode! What the heck?

IIRC, SS12 is Schottky diode. They're usually located in memory power circuit and burn when memory module is installed backwards.

[PeteS in CA]

Re: A bad diode! What the heck?

Here's the datasheet. It's a 1A, 20V schottky rectifier. I'd suggest a 1N5817 over a 1N5819. Both are 1A, the '17 is rated for 20V and the '19 for 40V, but the V(F) of the '19 is higher than that of the '17, which may be a relevant factor in the circuit.