SOT23 transistor HELP!

[finntricky]

i have a video switch box with 3 AV outputs, this is a rear double screen video system in my car, the switch box started to smoke so unpluged the 12v supply,
on inspection of the internal board, i have a N010X SOT23 that has burnt,
my problem is that i can't find any of these transistors with the same markings,
i have no idea of the values.
maybe someone here will know or maybe there may be an alternative, that i can replace with. added this pic that i found with google.
thanks for any help you can give in advance

[R_J]

Re: SOT23 transistor HELP!

They seem to be NK2302A

[redwire]

Re: SOT23 transistor HELP!

I find:
N010X alternates APM2302，SSS2302，ME2302，AP2302，STS2302，MT2302.
N029I alternates STS2304,Si2304，AO3406，NDS355AN，AP2304，APM2306，CES2304.

Is there a pic of the board, to see if these switch power for battery charger/camera or what. Some mosfets are only 16V rated which is too low for a car if switching 12V power.

[R_J]

Re: SOT23 transistor HELP!

The N010X could be the P-Channel mosfet, AO3401 or equivalent

[finntricky]

Re: SOT23 transistor HELP!

I find:
N010X alternates APM2302，SSS2302，ME2302，AP2302，STS2302，MT2302.
N029I alternates STS2304,Si2304，AO3406，NDS355AN，AP2304，APM2306，CES2304.

Is there a pic of the board, to see if these switch power for battery charger/camera or what. Some mosfets are only 16V rated which is too low for a car if switching 12V power.

here is a pic of the board, i have arrowed the N010x,
i thought it was N channel, but during my search have also come across P channel ?

[finntricky]

Re: SOT23 transistor HELP!

also taken some close ups

[R_J]

Re: SOT23 transistor HELP!

I would guess it is a P-channel mosfet, Best to check the voltage on the source and drain pins, with respect to ground.
The 1AM seems to be a (S)MMBT3904L

[redwire]

Re: SOT23 transistor HELP!

It looks like a mosfet switching remote power to something. I would check the load it supplies/wiring is not shorted, like a second camera or the LCD screen. The mosfet would not just cook like that on its own because there are gate resistors. I would say it was overloaded and where is the fuse.

You would have to check the drain and source traces, where they go to confirm if it is P or N channel. Cathode of D1 looks like +12V power so if Q9 source goes to that (power) and drain goes to the load, it is a P-ch high-side switch. Q9 drain goes to three vias, so I would follow those- they probably go to the load so that means it's P-ch.
Samhop semi taiwan does not give marking codes, they have a STS2301 P-ch. I would put in AO3401.

Lisen PBC3117-1-01 Main V1.1

[finntricky]

Re: SOT23 transistor HELP!

you are right redwire, there was a short on a video wire, inner and outer, only found it after the burn out of the N010X when i was checking the mini 8 pin din plug and socket. so im going to need a new cable as well.
to be honest, this is the first time i have had a look at something like this, i im at a total loss as to where to start, so i will buy some of the P channel, as this seems to be the best guess, what would happen if i put the wrong one in ?

[redwire]

Re: SOT23 transistor HELP!

OK that makes more sense.
Nothing can really go wrong putting in a new P-ch mosfet. The AO3401 has better specs than the other generic parts, and all have the same pinout.

[finntricky]

Re: SOT23 transistor HELP!

just to let you guys know, replaced the sot 23 with the A03401, and all is working fine,
next mission is to try and find the 8 pin slim mini din extension lead to go from the switch box to the monitor, can't seem to find anywhere in UK to buy them from.