Rumba short circuit

Hey guys,

i recently burned down my Rumba Board caused by an short circuit between the fan and the Motor.
As i got a Black Rumba i can´t really see what exactly burned down, but it seems like its the first Elko (50v, 47µF) after the power supply. (or at least its something in this area)
Is that guess legit? The elko smells burned and my multimeter shows weird results (unlike the other elkos)...



if its legit can i replace it with this elko?

ps: board lights up blue, usb works but windows doesn´t recognize the board anymore...

thanks in advance!

Edited 3 time(s). Last edit at 01/07/2014 07:13PM by mrc.

I looked at the schematics and the Elko im talking about is C1,
its the first elko after my power supply so does it makes sense that it burns first when a short circuit happens?

It doesnt make much sense for that to fail, unless voltage got over its rating or it got applied in reverse. In which case probably other parts are burned also - that cap most likely wouldnt fail alone.

Also, you cant measure caps in circuit unless you have an ESR meter. The funny readings could be because of other components. You would need to desolder it, measure it alone, then draw conclusions. But fail mode usually means it shows visually, so perhaps its not that. You can replace it with virtually any cap at that voltage rating. The input capacitor doesnt need specific esr rating like the output caps, but does need a rating 1.3-1.5 times higher than the actual supply because switchmode regulator has the tendency to raise input peaks like that. So the 50v rating should be in order, more than ok for that.

As you do have a multimeter, you should measure diodes D6 and D1, if they conduct and block correctly. Resistance of MFR500 against datasheet. Also, measure the resistance lt1933 between input side and gnd, and again between output and gnd, should not be too low values. If the above are ok, desolder that capacitor C1? and measure it alone. Then you should be able to draw some conclusions. Also if any of the prior measurements fail, also check D5, hopefully that should be ok - but just in case.

After big help from Hardwarekiller its clear that both Processors and all Stepperdrivers are defect.
So its basically completely broken, all other parts (D6, D1, C1 ...) are intact.

Anyway big thanks for your help!

Edited 1 time(s). Last edit at 01/22/2014 07:13AM by mrc.