<div><div dir="auto" style="font-size:1rem;color:rgb(49,49,49);word-spacing:1px">I'm ot sure if this is helpful because I can't see any of the original attachments. What does your display look like?</div><div dir="auto" style="font-size:1rem;color:rgb(49,49,49);word-spacing:1px"><br></div><div dir="auto" style="font-size:1rem;color:rgb(49,49,49);word-spacing:1px">Is the problem similar to this? </div><div dir="auto" style="color:rgb(49,49,49);word-spacing:1px"><br></div><div dir="auto" style="font-size:1rem;color:rgb(49,49,49);word-spacing:1px"><div><img src="blob:null/0b810a24-750c-4694-92bc-24d174816eab" class="" style="max-width: 100%;"></div>If so, the problem is the display. The Keithley 2110 VFDs go bad with age and I suspect other displays can suffer the same fate. The fix was always to replace the display like this guy covers: <a href="https://youtu.be/wXQdo42C6pE" target="_blank" style="font-size:1rem">https://youtu.be/wXQdo42C6pE</a></div></div><div dir="auto" style="font-size:1rem;color:rgb(49,49,49);word-spacing:1px"><br></div><div dir="auto" style="font-size:1rem;color:rgb(49,49,49);word-spacing:1px"><span style="-webkit-tap-highlight-color: rgba(0, 0, 0, 0);">On Sat, Jan 15, 2022 at 1:25 PM The MacDougals via TriEmbed <<a href="mailto:triembed@triembed.org">triembed@triembed.org</a>> wrote:</span><br></div><div><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div lang="EN-US" link="blue" vlink="purple" style="word-wrap:break-word"><div class="m_1747954337305765983WordSection1"><p class="MsoNormal">The display blinked back on at full intensity for a short while yesterday!<u></u><u></u></p><p class="MsoNormal">I believe it is the back light of the LCD that is the issue.<u></u><u></u></p><p class="MsoNormal"><u></u> <u></u></p><p class="MsoNormal">---> Paul<u></u><u></u></p><p class="MsoNormal"><u></u> <u></u></p><p class="MsoNormal"><u></u> <u></u></p><p class="MsoNormal"><u></u> <u></u></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 <<a href="mailto:triembed-bounces@triembed.org" target="_blank">triembed-bounces@triembed.org</a>> <b>On Behalf Of </b>The MacDougals via TriEmbed<br><b>Sent:</b> Saturday, December 18, 2021 3:02 PM<br><b>To:</b> <a href="mailto:triembed@triembed.org" target="_blank">triembed@triembed.org</a><br><b>Subject:</b> Re: [TriEmbed] Substitute transistor<u></u><u></u></p></div></div><p class="MsoNormal"><u></u> <u></u></p><p class="MsoNormal">I replaced the transistor with an exact match from ebay and a couple of electrolytic caps (at Carl’s suggestion).<u></u><u></u></p><p class="MsoNormal">The display is still dim. Oh well.<u></u><u></u></p><p class="MsoNormal"><u></u> <u></u></p><p class="MsoNormal">---> Paul<u></u><u></u></p><p class="MsoNormal"><u></u> <u></u></p><p class="MsoNormal"><u></u> <u></u></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 <<a href="mailto:triembed-bounces@triembed.org" target="_blank">triembed-bounces@triembed.org</a>> <b>On Behalf Of </b>The MacDougals via TriEmbed<br><b>Sent:</b> Friday, November 26, 2021 9:11 PM<br><b>To:</b> <a href="mailto:triembed@triembed.org" target="_blank">triembed@triembed.org</a><br><b>Subject:</b> [TriEmbed] Substitute transistor<u></u><u></u></p></div></div><p class="MsoNormal"><u></u> <u></u></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<u></u><u></u></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<u></u><u></u></span></p><p class="MsoNormal"><span style="font-size:14.0pt">marked B1238, so I assume it is a 2SB1238, which is obsolete.<u></u><u></u></span></p><p class="MsoNormal"><span style="font-size:14.0pt"><u></u> <u></u></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" target="_blank">https://www.digikey.com/en/products/base-product/rohm-semiconductor/846/2SB1238/30307</a><u></u><u></u></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.<u></u><u></u></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.<u></u><u></u></span></p><p class="MsoNormal"><span style="font-size:14.0pt"><u></u> <u></u></span></p><p class="MsoNormal"><span style="font-size:14.0pt">Anyone want to help me find a replacement?<u></u><u></u></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.<u></u><u></u></span></p><p class="MsoNormal"><span style="font-size:14.0pt"><u></u> <u></u></span></p><p class="MsoNormal"><span style="font-size:14.0pt"><u></u> <u></u></span></p><p class="MsoNormal"><span style="font-size:14.0pt">---> Paul<u></u><u></u></span></p><p class="MsoNormal"><span style="font-size:14.0pt"><u></u> <u></u></span></p></div></div>_______________________________________________<br>
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