d10 diode

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something died inside my lcd for my gamecube, opened it up and next to the power input there was a little what looks like a diode that fried and cracked in half, on the board it says d10 where the diode was, does that mean anything? and if its any help, its a 12v 5a in cord that goes with it. the part looked like 1 of those below.
 

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Hi,

There must be some misunderstanding here, as the "Ah" rating of a battery merely relates to how long it will last in use from a full charge. i.e. The 22Ah you quote would power a device which draws say 1 Amp for 22 hours before the battery is exhausted (or 22A for 1 hour, at the opposite extreme).

If the original battery is merely 5 Ah, as you suggest, it would supply 1 Amp for merely 5 hours (or 5 Amps for 1 hour etc.)

So this difference in "Ah" rating cannot, in itself, have been the cause of the failure. Under normal circumstances, the circuit will determine how much current will be drawn from the battery, as the current is 'drawn' rather than it being 'pushed' or forced, as you suggest.

Are you sure that the battery voltage of 12v is correct here?

Regards,:)
 
Hi,

Something just occurred to me here. I am not familiar with this piece of equipment at all, but looking back at your original post, it suggests to me that it might usually be powered by a "wall-wart" type of transformer/power supply, rather than a battery.

If this so, it could be that this is an AC supply, and you might see something to this effect on the PS unit. It could say something like: Input 110 Volts AC, output (say) @ 12 V AC at ??? mA.

If this is so, then the problem is that you have used a DC supply from the battery, and I also guess that this diode *could* be damaged by this, perhaps.

Unfortunately, the diode number (D10) on the circuit board, does not help in identifying the correct part to use here, it merely shows which diode this is to enable you to refer to it on a circuit diagram.

Also, this might not be the only damage which has occured here, as a lot of (most!) electronic components can be damaged without showing any external signs.

Let us know if the PS is as I suggested above, and it might be possible to offer some more help.

Regards, :)
 
The only thing to note is the voltage. Try powering a small 12v globe from 8 dry cells and from a car battery, same thing.

The diode is probably there to protect from reversing the power leads by accident. If you only used 12v, that probably didn't damage it unless your car's regulator is toast.

The other possibility is over current. A failure further in (a short for eg) may have taken out the diode.
 
WordUpOnLCDs said:
well it runs of 12v 5a from a car cig lighter terminal

In that case, it cannot be intended to use AC voltage as I had wondered, but as I said, this was just a thought here, in the hope it might help.

Although car batteries are nominally 12v, they will measure up at a minimum of 12.75v (usually) and sometimes up to 13.5-ish volts, or even more if the engine is running.

However, somehow I don't think this is the problem, and now it is established that DC voltage is needed here, the diode is most certainly there to prevent reverse connections from causing any harm, as Indm says.

My guess, is also as Indm's suggestion, in that something elsewhere has caused an unusually high current draw, and this was too much for the diode to handle. It could have just 'tipped the balance' and caused this failure, if the car battery's voltage is on the high side, as shown above.

Can you see any markings on the diode, itself, around the body of it, or is it too badly damaged? I would expect to see something like 1N400? here (1A rating), with the last number indicating the max. voltage (1N4001 = 50v). If you can post any numbers, we should be able to tell you exactly which diode it is.

Anyway, if this is all that has been damaged, almost any small power diode in this series (or maybe 1N5401 for 3A) should be adequate for 12V operation, and you should be able to pick something up locally without too much trouble as these are very common parts.
Take note that the band around one end needs to be orientated the same way as the damaged diode, or no current will be able to flow, as these diodes work like a 'one-way' valve for the passage of DC current.

I hope this helps, but without any further information from you, I don't see how anyone could say any more.

Regards,:)
 
Hi,

If it helps, I have seen many of these diodes go bad like this, but they rarely disintegrate into little pieces.

Also, (usually) their body material is so hard that even any 'flash-over' will not harm the markings on the case. Often, the 'flash' will create some carbon deposits on the outside which can be cleaned off with a cotton bud dipped in some cleaner, and this will not (normally) erase these markings. This carbon deposit, can hide the markings, but I am sure it will have some on the device, somewhere.

Using a good light, and say a magnifier if necessary, it should still be possible to make out the markings, or at least part of them.
You may need to unsolder the device to see all around it, but make a careful note first of which end the marked 'band' is.

The writing will normally be around the body, rather than along it, but it could be either way.

Because I know what is *likely* to have been used here, if you can post any info. (even only parts of the lettering, will help) it is more than likely we can correctly identify the original part.

Otherwise, I am sure we can suggest a 'safe' alternative to use here, which you should be able to get hold of readily. If "worst comes to the worst", I will send you a suitable diode FOC, but I am in the UK, and this would take a little time.

Of course, if there is some other problem which has caused this failure, replacing the diode alone will not necessarily get you going again, but it is unlikely that repacing this and trying again, will cause any more damage.

Regards,:)
 
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