You can go to the following website to download a copy of the service manual for your TV:http://www.eserviceinfo.com/downloadsm/17900/Toshiba_32hf72%2032hfx72%2036hf72%2036hfx72.html
It is a multipart RAR archive so you will have to download all of the parts and then use either Winrar or Winzip to unpack it. You will have to have the free Adobe Acrobat Reader available on the Adobe site to read the manual.
of the manual shows the part that you are looking for, It is about a third of the way down in the second column. Location # KB01
, part #23906805
, described as IC, REMOTE PHOTO RECIEVER, PIC-TB17
. Page 39
in the manual shows you the CONTROL-1 BOARD PD0651
. On the left hand upper side of the board the first component is labeled POWER SA05
. Directly beneath that part is the KB01
, which is the sensor you are looking for. You should be able to order the part from the shop that the repair guy that you mention in your question. Once you receive it, all you have to do is find the location on the parts placement picture in the manual, desolder and remove the old one, and then solder in the new one. You mention that you have some experience in radio/tv repair so I'm assuming that you are okay with that procedure. There are numerous sites all over the web that show and discuss the procedure. If it has been awhile since you've done that type of repair you might want to do a little practicing. Like all electronic parts the sensor is sensitive to heat damage.