[SOLVED] short-circuited Pins 1 (3.3V) and 9 (GND) - periphery dead

[Panoptis]

I know, I'm stupid...

Good news is that the chipset seems to be fine. Got HDMI output and System (SD) boots up.
USB, Ethernet and I/O Pins are dead.

At least the FTK3407 Transistor got fried.
Can this damage be repaired? Or is it likely that more components were affected?
What could I use as a replacement?

Any help is appreciated!

[phaseshifter]

any low voltage p type fet inc diode..most do have ..browse ftk3407 if you can solder it..but about the rest of the board who knows

[joerg]

If you can desolder the Q1, you then could check if the VDDAO_3V3 is there and also if there is no short circuit on the VCC3V3 side. If everything fine you can make test wise a jumper from VDDAO_3V3 to VCC3V3. Any stable 3.3V connected to pin1 would do this also. If you find everything working, you have luck! Because it would be possible to solder a transistor with fine equipment and a sure hand...

[Panoptis]

If you can desolder the Q1, you then could check if the VDDAO_3V3 is there and also if there is no short circuit on the VCC3V3 side. If everything fine you can make test wise a jumper from VDDAO_3V3 to VCC3V3. Any stable 3.3V connected to pin1 would do this also. If you find everything working, you have luck! Because it would be possible to solder a transistor with fine equipment and a sure hand...

Thank you for your detailed response @joerg!
Did exactly that, desoldered the broken Transistor and left a solder bridge between VDDAO_3V3 and VCC3V3.
Everything seems to be working so far (tested: USB, Ethernet, IR, eMMC, SD, IR)

Did not leave the N2 running for long, could someone bother to briefly explain what the purpose of that circuit is? What would happen if I left it like that?

Thanks @phaseshifter for the explanation about the Transistor.
Would this be a suitable replacement?
(I could not find a FTK3407 with quick delivery in europe)

[mad_ady]

@Panoptis: could you make a more detailed description of what went wrong, where tghe transistor is located, how you identified it was broken and how you bypassed it? I expect more people will run into this issue sooner or later...

[joerg]

@Panoptis: The replacement you found has 3A maximum current. Maybe it is enough, who knows. I found this type TSM650P03CX on reichelt.de in germany, it has also 4A and low on resistance. I don't know if you can order from there or you could find another shop.

[Panoptis]

@Panoptis: could you make a more detailed description of what went wrong, where tghe transistor is located, how you identified it was broken and how you bypassed it? I expect more people will run into this issue sooner or later...

Sure.

Snatched a spdif audio LED from an old Mainboard and got it working with the N2.

Sound was gone and I fond it was due to a loose contact at the wire coming from the spdif socket (probably bent it too often when fixing the socket to the N2 case with a little hot glue).
That's when I should have switched the N2 off and repaired the connection but I instead jiggled it a bit to get sound back until the end of the movie
... vcc wire came of completely and touched GND, puff of smoke from wire and N2. No more power on 3.3 V lane.

Turned it off and examined the Board with schematic open (memorized what side of the N2 the smoke came from) and saw the damage on the mosfet (see my first post) that was also clearly important for the 3.3v lane as I could decern from the schematic.
EDIT: as to where it is located, you can see the sys and pwr LEDs in the Image.

Then I followed @joergs post, used a cheap soldering kit I already had and carefully removed the FTK3407 with tweezers and soldering iron, one connection after the other.
Used a tiny amount of solder to bridge source and drain and since it seems everything else seems fine, ordered the TSM650P03CX joerg recommended.
Will report when it arrived and I soldered it (will be a few days).

Still don't know what the Q1/Q2 mosfets and the circuit (second image in Imgur gallery in my first post) does exactly... I guess voltage stabilization?

[mad_ady]

Sorry, I hadn't followed the imgur link. Now it's more clear.

[phaseshifter]

optics work just fine on the n-2 look here..i salvaged my optic Txmtr out of a junked dvd player..

viewtopic.php?f=181&t=34528#p252166

this whole thread is informative...

[Panoptis]

optics work just fine on the n-2 look here..i salvaged my optic Txmtr out of a junked dvd player..

viewtopic.php?f=181&t=34528#p252166

this whole thread is informative...

Yeah, also read that. Had to adjust mux groups setting in ubuntu.
In CoreELEC it was already correctly set to pin 13.

[Panoptis]

Not the best soldering job but good enough.
Everything seems to work so far!

Consider this resolved.

[odroid]

Glad to hear you fixed your board by yourself.

[cobric]

Not the best soldering job but good enough.
Everything seems to work so far!

Consider this resolved.

Hi Panoptis, just saw your thread and problem and unfortunately I have same problem and symptoms (dead Ethernet and USB but booting from SD card is working), please see here

Just to ask you on which things I need to pay attention when buying replacement transistor if I can't find TSM650P03CX here in Croatia? I'll need to go to electric parts shop and ask there for transistor but I don't know what parameters are important. Also my soldering skills are far from yours so I'll need to find someone here with steady hand to replace it.

Any help would be appreciated, but seeing that you managed to repair yours gives me hope

[mad_ady]

A phone repair shop should have the necessary tools and skills. Or a local electronics hacker space.

[cobric]

A phone repair shop should have the necessary tools and skills. Or a local electronics hacker space.

Thank you, I'll see with them. They offer me this one http://www.aosmd.com/pdfs/datasheet/AO3401A.pdf as replacement. Can anyone tell me if that is ok?

Thanks!

[Sholander]

You can search yourself for an equivalent. AO3401A isn't among them.
Here is one searched cross-reference table for FTK3407: https://alltransistors.com/mosfet/crsea ... caps=SOT23

[cobric]

You can search yourself for an equivalent. AO3401A isn't among them.
Here is one searched cross-reference table for FTK3407: https://alltransistors.com/mosfet/crsea ... caps=SOT23

Thank you, I don't know if it is important to have Vgs > 20V, but @Panoptis installed TSM650P03CX which has Vgs 12V - same as AO3401A so I figured that it will be good enough to replace FTK3407 as one user successfully replace it with it. I'll try to contact @Panoptis to find out if he had any problems after few weeks using it.

Thank you, I'll certainly do more research.

[ruppi]

Hi cobric,

AO3407A is a replacement for FTK3407.

-BR-
Ruppi

[cobric]

Hi cobric,

AO3407A is a replacement for FTK3407.

-BR-
Ruppi

Hi Ruppi,

Thanks, I already bought AO3407A as I saw that it will be better fit then AO3401A. I left device for soldering new transistor (AO3407A) today at local electric shop as they will do it more professionally then me
I'll report back as soon as I get it back and try it.

Thank you all!

[cobric]

Hi all!

Just got back my Odroid from soldering new transistor and I'm happy to say that everything works!
Guys at shop did great job, and transistor AO3407A is perfect replacement.

Thank you all for your help!

[tobetter]

Hi all!

Just got back my Odroid from soldering new transistor and I'm happy to say that everything works!
Guys at shop did great job, and transistor AO3407A is perfect replacement.

Thank you all for your help!

Congratulation!!!

[Sholander]

Hi all!
Just got back my Odroid from soldering new transistor and I'm happy to say that everything works!
Guys at shop did great job, and transistor AO3407A is perfect replacement

Thank you all for your help!

Congrats (čestitam Enjoy your N2, and don't do anything in a rush with it

[mad_ady]

Perhaps this fix should be wiki-fied, in case it happens on GPIO short-circuit. I expect it will happen to more people over the course of time...
Kudos to Hardkernel for being user-fixable!

[mad_ady]

We've made a WiKi page for DIY repairing.
https://wiki.odroid.com/odroid-n2/hardware/repairs