Hi electronician detectives out there!

Now I have dissassembled my dads TV-set...  I have found that the main=
 supply switch transistor is fried, and components around it seem OK, so I=
 am looking for what to replace it with.

It is an isolated TO220/SOT186, labeled:

  ON
 4827
PHm423

I don=B4t even know what manufacturer it is.  I thought it to be ON=
 semiconductor, maybe Philips, but neither Google, or ON semiconductor nor=
 Philips website searches could find anything useful on 4827.  Tried a lot=
 of sites and search engines and criteria, and finally found searching for=
 ON4827 at http://www.electrospec-inc.com/ gave a list containing an item=
 "4827BUT12AF", probably an alias, bot how identical is BUT12AF?

BUT12AF:
http://www.semiconductors.philips.com/pip/BUT12F.html#datasheet

Data seem to be somewhat OK.  I can se from the circquit it need to be a NPN=
 switcher in a flyback design, 230VAC mains, so it is possible, but the Uceo=
 of 450V for the BUT12AF seem too little.  But it can sustain Ucesm (peak)=
 of 1000V so it is possible...?

However while replacing a tranny it is important to have enough voltage=
 capacity, enough hFE and good switching time so i would prefer to find the=
 original manufacturer of "4827"

Any ideas?

(BTW, while i begun writing this letter my old TV, that my dad borrowed a=
 couple hours ago, let out lot of smoke and he threw it out... Spooky.  Now=
 i have checked the mains voltage in his house and it IS OK.   One more to=
 repair...)

Thank you
/Morgan=20

--
http://www.piclist.com hint: To leave the PICList
mailto:piclist-unsubscribe-request@mitvma.mit.edu