Please help identify component

[trebla]

While installing Coolermaster Hyper 6 cooler on EPoX 8KDA3J (AMD Athlon 64, Socket 754) motherboard I broke a component which interfered with cooler support frame.

This much I know about it.
Marking: WW1 / 46 (WW1 along the longer side and 46 rotated 90 degrees, most likely 46 is a lot number)
Package: SOT23-3
ID on board: D39 (also D6 is same)
Location: Between CPU and ATX 20-pin connector)
Connections: Lead 3 goes to ATX 20-pin connector lead 8 (PWR-OK, aka POWER GOOD), lead 2 sinks into any of the middle layers, lead 1 can be followed on the picture.

Measured resistance on leads of the another, non-broken one near the CLEAR CMOS jumpers (position D6), any combinations between leads gave readings of 600K or more up to infinity. Measurements done with Fluke 73 multimeter.
No lead connected with ground.

Have been searching on the net for a week but still no luck.
Based on electrical measurements cannot be a diode, transistors are marked with Q on schematics, colleagues have suggested Zeners, field transistors, JFETs, voltage supervisors.

WWx markings seem to be exceptionally rare, only real match with marking is **broken link removed** ,see p2, marking section.
Near matches are **broken link removed**.

E-mail to EPoX support has given no reply.

Could anybody help to figure out the component, either original or if knowing exact purpose of it, suggest a replacement.
I'd rather like to save the board that cost me 100 Euros than throw it away.

Thanks in advance.

 

[Nigel Goodwin]

I would suggest it could be a diode, as it's labelled 'D', there are similar looking devices nearby labelled 'Q' which are probably transistors. These designations are commonly used in circuits.

As it's got three legs, it might even be a double diode, or one pin may not be used, or connected internally.

Have you tested them with a diode test function?, rather than just on an ohms range?.

 

[trebla]

I would suggest it could be a diode, as it's labelled 'D', there are similar looking devices nearby labelled 'Q' which are probably transistors. These designations are commonly used in circuits.

As it's got three legs, it might even be a double diode, or one pin may not be used, or connected internally.

Have you tested them with a diode test function?, rather than just on an ohms range?.

Yes, "D" would go for diode. Have not tested diode function. Will try on monday.

 

[zevon8]

Here's a great website for SMD codes:

http://www.tkb-4u.com/code/smdcode/indexsmdcode.php

According to their database,

http://www.tkb-4u.com/code/smdcode/smdcode4.php

your part may be a BAS40-06, I checked Philips, instead of Siemens and they mark theirs with a 46.

Hope this helps

 

[trebla]

the results of onboard diode function test for the known good one are the following:

red-black
1-2->OL
1-3->286 ohm
2-3->beep

black-red
1-2->beep
1-3->OL
2-3->OL

my skills level is too low to figure the diode configuration out of this.

zevon8 -> yes if we look at the 46 part of the marking, it is Philips BAS40-06
if we look at the WW1 part its BAT54C according to **broken link removed**

at least some manufacturers use in such cases the 46 part of the marking as lot number.

 

[trebla]

OK, here are the results of off-circuit diode function measurements for the known good one.
done with a cheapo Mastech M-830B tester

component leads 1 and 2 on the double lead side, 1 left and 2 right , 3 on the other, single lead side. (Philips style of marking)

pos-neg
1-2 -> OL
1-3 -> 200
2-3 -> 200

neg-pos
1-2 -> OL
1-3 -> OL
2-3 -> OL

these results to some extent confirm the component to be a Philips (manufactured in China) BAT54C