SMD Transistor WU1
If you repair SMD circuit board and found a smal SMD transistor WU1, then you should expect that there is another part number that you should search for. The part number is DTA144 which is a PNP digital silicon transistor. This means that if you could not locate or buy the smd transistor WU1, you can buy the DTA144 as replacement. If you download the PDF file of DTA144 HERE, you could see the word WU1 under MARKING.
This transistor was found in HP formatter board byone of the ERG members.