Garmin 2597 LMT Circuit Board Repair/Component ID

[Quasimodo]

Hi,

I am looking at repairing this Garmin 2597 LMT GPS which I picked up recently.

When the battery is charged, it works ok but the battery won't charge up with a wall/car charger nor will it run off the supplied power from either source.

Initially I thought it would be a simple broken usb connector but removing the cover revealed more carnage inside.

The small 6pin device (dimensions 2mm x 1.25mm) under the silver square is blown out.

When plugged into a computer USB port, it seems to drag down the USB circuit of the computer with mice/keyboards ceasing to function.

The markings on the damaged chip seem to be either CO7NN or CD7NN although it is a bit difficult to read where it is damaged.

The only reference I can find to these markings is an Chinese document which is a list of chip markings on
what they call "Power Current Limit Switch Chip Screen Printing BXXXX Package SOT23-5 Model SFST0012"

I am pretty sure the blown device has 6 legs though.

Does anyone have a clue to what it might be or how to identify it further?

Thanks in advance for any help.

Dave.

[coromonadalix]

smt code book

http://www.marsport.org.uk/smd/mainframe.htm

co7 gives this ??

C07    DDX143TU    Dio    DO    SOT363    dual dtr pnp/npn 50V 0.1A R1 4k7
C07    DDX143TK    Dio    DO    SOT26    dual dtr pnp/npn 50V 0.1A R1 4k7

[amyk]

Code: [Select]

C07xx DCX143TH   SOT-563 COMPLEMENTARY NPN/PNP PRE-BIASED SMALL SIGNAL DUAL SURFACE MOUNT TRANSISTOR
COxxx AAT4280IGU-1-T1 AAT4280 SOT23-6 Slew Rate Controlled Load Switch
 Check the pinout and where the traces go. If pins 4 and 6 are connected together, as well as 2 and 5, then it's probably the second one; otherwise it could be a complementary transistor but I doubt it. A load switch makes far more sense in this application.

[Quasimodo]

Thanks everyone for the leads - will check the pin connections when I get some spare time in the next few days.

I will report back if have any success.