It is located here:

I think it as diode to protect from accidental (or not) polarity inversion.
Besides the smell and smoke, the eeepc works only connected to power, without the battery?
If works, simple clean and replace by a ordinary rectifier diode, like a 1N4007.

I think i got it:
The component seams to be a "safety" for to much electricity.
I removed the burn pieces, and used a small wire to connect the two points, and when i now give it electricity,
there comes no smoke or smell. So i'm going to melt it fast there.

Risky, i know, but i think it's worth a try.

I guess you're right 126andy,
i saw pksato said i could replace it with a "ordinary rectifier diode, like a 1N4007", after som googling i figured out what he ment.
I didn't have a dictionary aviable, so i didn't understood what a "diode" was, but of course it was the "safety-component" i was talking about in the last post. (in norwegian: "sikring", (safety)) I think i go buy a diode, rather then burn down my house.
The wire i was talking about was actually a wire from a diode, but as you said andy, i don't think that is safe enough.

Is this the what i'm looking for?
http://musikkogelektronikk.dynmab.as/ma … amp;id=361

Last edited by Jossa (2008-03-13 4:53:26 pm)

What is the diffrent between a fuse and a diode?
I'm kind of confused, but i see that fuse means "sikring" in norwegian.

The wire i was talking about was the wire in the middle of the green fuse:


Mjolinor: As i said earlier in the tread, my Asus Eee PC actually worked just fine after i blowed the diode, until the battery ran out of power. Do you still think there is more components been damaged?

Fuse -> http://en.wikipedia.org/wiki/Fuse_(electrical)
Diode -> http://en.wikipedia.org/wiki/Diode

Reverse diode and fuse can be used to protect eletronics against inverse polarity from power supply.
Asus, don't put a fuse on eeepc main board.
And your old car adapter don't have short circuit protection.

I don't figure out the type of original diode, but, is possible that not a simple rectifier diode, and can be not use to reversed voltage protection. Need more analyze of circuit in this region.


** Sorry, I can not help you much, I am illiterate in English.

use without diode only if no chance of reverse polarity occuring, car normal high end voltage approx 14v (on charge), I think the required voltage is about 9-10v! seven (silicon) diodes with sufficient current rating strung inline at 0.6v drop across each would drop it from 14v to 9.8v put an amp meter inline and test out? see if current reasonable comparing readings with a mate or known "normal" with/without battery in, when known safe to use insert "inline" fuse to suit rating.
I am considering doing some  current demand checks on mine with the three stage clocking etc. will be usefull to know power demand at diff. settings wifi disabled etc. Anyone done that already? cheers

Jossa wrote:

Mjolinor wrote:

The diode being there or not will not stop the eee from working. (...) If there were no further damage then the eee would be fine without it using it's own power supply.

As yours is not working from the mains power then there is more damage somewhere. (...)

The diode not being there will not stop the eee from working, but it makes it impossible to charge the battery, or use the Eee PC without the battery.

Mjolinor is likely correct, that diode will only provide some protection against reverse voltage. Not having will not affect the operation of the laptop in any way (battery or power supply operation). What likely happened though is that more circuitry in your Eee was damaged when you plugged in that other supply, particularly the regulators which provide power to the laptop when running on an external power supply. If that got smoked (may not be visible) then the power supply won't be able to power up the laptop or recharge the battery.

Another alternative is that the diode is used in a switching power supply (regulator) to regulate the incoming voltage form the power supply to correct levels. In that case, replacing it with a wire would likely have done more damage to the unit.

The short answer is that you need to replace that component and then do more testing to see what else might be damaged.

bryfos wrote:

use without diode only if no chance of reverse polarity occuring, car normal high end voltage approx 14v (on charge), I think the required voltage is about 9-10v! seven (silicon) diodes with sufficient current rating strung inline at 0.6v drop across each would drop it from 14v to 9.8v put an amp meter inline and test out? see if current reasonable comparing readings with a mate or known "normal" with/without battery in, when known safe to use insert "inline" fuse to suit rating.
I am considering doing some  current demand checks on mine with the three stage clocking etc. will be usefull to know power demand at diff. settings wifi disabled etc. Anyone done that already? cheers

I haven't done this (diodes to lower voltage) with my 3e, but I have done so with other DC sourced devices and it works as advertised.

That's when something like this comes in handy.... fancy regulators will even do their down "downstepping", for lack of a better word.

http://cgi.ebay.com/ws/eBayISAPI.dll?Vi … amp;ih=015

Have you tryed the eeepc without the diode or wire across it. Do NOT leave it if it charge the battery without it we know the it will work if it is put back in the right way. I had the same problem with a wireless acess point when a friend pluged in the wrong voltage and it - in the center of the plug that he pluged in. it is still working. I just removed it and made sure it will work with out diode first then i put in a diode  the right way around the diode was 1A for protection.

did you put the diode in the correct way round? try swapping it.