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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple style='word-wrap:break-word'><div class=WordSection1><p class=MsoNormal>I replaced the transistor with an exact match from ebay and a couple of electrolytic caps (at Carl’s suggestion).<o:p></o:p></p><p class=MsoNormal>The display is still dim. Oh well.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>---> Paul<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p><div><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b>From:</b> TriEmbed <triembed-bounces@triembed.org> <b>On Behalf Of </b>The MacDougals via TriEmbed<br><b>Sent:</b> Friday, November 26, 2021 9:11 PM<br><b>To:</b> triembed@triembed.org<br><b>Subject:</b> [TriEmbed] Substitute transistor<o:p></o:p></p></div></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><span style='font-size:14.0pt'>My microwave display suddenly went very dim. I opened it up and found a discolored<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt'>spot on a circuit board feeding the display (see attached image). That component is<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt'>marked B1238, so I assume it is a 2SB1238, which is obsolete.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt'><a href="https://www.digikey.com/en/products/base-product/rohm-semiconductor/846/2SB1238/30307">https://www.digikey.com/en/products/base-product/rohm-semiconductor/846/2SB1238/30307</a><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt'>Medium power transistor( 80V, 0.7A) 2SB1189 / 2SB1238 Features 1) High breakdown voltage, BVCEO= 80V, and high current, IC= 0.7A.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt'>2) Complements the 2SD1767 / 2SD1859. Absolute maximum ratings (Ta=25C) Parameter Symbol Limits Collector-base voltage VCBO −80 Collector-emitter voltage VCEO −80 Emitter-base voltage VEB O −5 Collector current IC −0.7 C.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt'>Anyone want to help me find a replacement?<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt'>I dug through my Dad’s stash of old electronics and found a TIP30B, which looks like it might work.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt'>---> Paul<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt'><o:p> </o:p></span></p></div></body></html>