A7V333 please help identify part

[LazyBastard]

Beside the battery, black 3-legged animal labeled D4. Some moron decided to
clear the cmos with the unit powered up and this wonderful D4 emitted the
magic smoke. Now setup has to be completed every time the unit is unplugged.

Can anybody identify this part for me?

Thanks.

[Paul]

In article <oP_pa.165994$Vzu.1...@news02.bloor.is.net.cable.rogers.com>,
"LazyBastard" <this...@hotmail.com> wrote:

Here is an imaginary drawing. Your three legged device could be
a common cathode dual diode. That would burn up nicely if node 3
was grounded, while node 1 and node 2 had power sources connected
to it.

|\ |
1 _____| \|__________
| /| |
|/ | |
|___________ 3
|
|\ | |
2 _____| \|__________|
| /|
|/ |

An example of the technology is here:

http://www.fairchildsemi.com/ds/BA/BAT54C.pdf

The BAT54C is a common cathode diode, suitable for diode ORing
two power sources. Since there are many different devices like
this, and they are available in common anode, common cathode,
head-to-tail, single diode, etc., you cannot tell what it is
without a multimeter and/or curve tracer. You would
have to characterise a good one, to buy an exact replacement.
I don't know if these are large enough to have lettering on
the top of them or not.

Be careful, as if the lithium battery gets connected to the
PC power supply, the little coin cell battery could go flying
across the room!

HTH,
Paul

[LazyBastard]

I appreciate the description, but I already know all that. Problem is that
1) the chip is burned, so reading it is impossible. 2) the chip is burned,
so I can't test it - it don't work. <G>. I was hoping that someone here
would have already looked it up and have the part number handy, otherwise
I'll have to locate another one of these boards and plug my equipment into
it.... OR, I'll have to remove the battery socket and see where everything
connects to (I hate doing that).

"Paul" <nos...@needed.com> wrote in message
news:nospam-2404...@192.168.1.177...

[Paul]

In article <Qh0qa.133986$BQi....@news04.bloor.is.net.cable.rogers.com>,
"LazyBastard" <this...@hotmail.com> wrote:

> I appreciate the description, but I already know all that. Problem is that
> 1) the chip is burned, so reading it is impossible. 2) the chip is burned,
> so I can't test it - it don't work. <G>. I was hoping that someone here
> would have already looked it up and have the part number handy, otherwise
> I'll have to locate another one of these boards and plug my equipment into
> it.... OR, I'll have to remove the battery socket and see where everything
> connects to (I hate doing that).

To help you out (by analogy), I looked at two motherboards that
are still in their boxes. I uses a small lens to read the top of
the diode. The top of the diode next to the battery on these
boards reads:

K45MD (tuv4x)

K45M4 (tua266)

The last two characters are turned sideways, so it actually consists
of two character strings "K45" and "MD", at 90 degress to one another.

Maybe that will give you some ideas.

Paul