Pic 16Fxx Battery Charger Help

[wbjunkie]

Have a BMW battery charger which I desperately need to repair.
Have studied the posts discussing how to build such a circuit on this forum. Have also seen the application note on the Pic Micro web site but am still lost.

Here is a picture of the circuit
http://rapidshare.com/files/172960057/bmw1.jpg.html

Anybody willing to take a guess at what the SMD 4 Pin IC which is under the 4 white leds dead center.

Also to its left is a white box marked T2 these are the only two items which are damaged / burnt and need replacing.
Thanks

[mat janssen]

If you mean the one with 1 pin left and 3 pins at the right side of the component than I can tell you that it is a small power transistor or a fet.
The middle pin of the left side is connected to the left pin.
If you can read something on it may be I can tell what it is then.

[wbjunkie]

here is another picture.
I have circled the items in doubt one is a white box labeled T2
The other is the IC with 3 legs and a thick top (Dead Center top)

If I could even have a look at a working unit it would help but the guys on the BMW forum are not much help nor are the guys who made this unit.

There are 4 points sticking out the epoxy and the PCB is soldered onto these 4 poles. They provide 15 volts a/c. My first problem is that my 7805 which powers the pic is not geting any input voltage. The input is traced back to the burnt component. So it must be taking the a/c voltage in and converting it to d/c before passing it on to the 7805.
If I short T2 the unit seems to boot up but I see smoke from the burnt IC.

The circuit looks identical to the ones you guys built here and to the application note on the Pic site. I can take a wild guess what it is. But really need a part number to buy a replacement.

[mat janssen]

When I look how this all is connected, then I think the T2 component is a fuse of 2 Amp slow, and the other component is a voltage regulator like 78M05 smd.

[wbjunkie]

I thought it was a fuse and shorted it that when the IC blew up.

The 7805 is actually the ic to the bottom right of the pic.
The burnt IC is what actually supplies the power to the 7805.

The IC is taking the 15-18 volts a/c from the transformer converting it to d/c and sending it to the 7805 guess I should supply 12 volts directlly to the 7805 and see if the pic boots up.

[Archangel]

The IC is taking the 15-18 volts a/c from the transformer converting it to d/c and sending it to the 7805 guess I should supply 12 volts directlly to the 7805 and see if the pic boots up.

Might just be a diode bridge or full wave diode and not an IC.

[wbjunkie]

considering both pins are connected to the black diodes I doubt this.
What are the chances of it being a LM317