Recently while plundering a scrap Toshiba laptop display for ceramic chip caps, I spotted a small 4 pin device with the Microchip mark on it, its like a medium sized SMD transistor 4.57 x 3.11 mm and has the number "5751" under the trade mark, entering the number (not knowing the prefix) on the microchip search gives no results and google gives a lot of tube data hits - my only hope is if anyone knows this device and can tell me the part number prefix.
Any help appreciated TIA.