Here are the pictures. It was late and I shorted 2 pins of the smart card reader ribbon connector. Don't know how such a stupid mistake, but this component on the other side of the board went up and smoke and now I need to figure out what it is. Close up

  • \$\begingroup\$ A board schematic would be amazing if anyone can find that, but I've searched for hours and found nothing. \$\endgroup\$ Apr 13 at 2:17
  • \$\begingroup\$ The component is marked Q7001 on the board. The letter Q is commonly used in the industry to mark Transistors or logic gates such as schmitt triggers. Guess it is a starting point. Can you peel of the top of the component and see if you can make reappear the letters on the component itself ? Do you have any relative with the same computer which could provide pictures of an undamaged part ? \$\endgroup\$ Apr 13 at 7:47
  • \$\begingroup\$ Does everything else on the laptop still work? \$\endgroup\$
    – HandyHowie
    Apr 13 at 10:26
  • 1
    \$\begingroup\$ FYI, when a component is visibly blown, it is often the case that there may be other components that are invisibly damaged. Such damage may have contributed to the failure of the component you have identified, or may have failed as a consequence of the visibly damaged component. In either case, replacement of the damaged component may not be the end of the story, but only one step in troubleshooting. \$\endgroup\$ Apr 13 at 11:49

1 Answer 1


From the 4 pins shorted together, the pinout corresponds to a SOT-23-6 single MOSFET. Here's an absolutely random datasheet from the internet, which has no relation to your component, but it's a SOT-23-6 MOSFET... so you get the idea:

enter image description here

If you shorted VCC and GND on the connector, then that's probably the MOSFET that controls the power supply for the smart card reader. That means most likely a PMOS in the VCC line.

You should desolder it and check the voltage on its source pin is indeed whatever supply voltage your smartcard reader wants. Then check continuity between the drain pins and VCC on your connector. If there is continuity, then it's a PMOS in the VCC line, and you can substitute with another PMOS of "suitable" specs... I'll leave that as an exercise to the reader, but if you know voltage, gate drive voltage, and maximum current, you'll be able to search for a PMOS that will work.


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