[TriEmbed] Substitute transistor

[The MacDougals]

The display blinked back on at full intensity for a short while yesterday!

I believe it is the back light of the LCD that is the issue.

 

---> Paul

 

 

 

From: TriEmbed <triembed-bounces at triembed.org> On Behalf Of The MacDougals via TriEmbed
Sent: Saturday, December 18, 2021 3:02 PM
To: triembed at triembed.org
Subject: Re: [TriEmbed] Substitute transistor

 

I replaced the transistor with an exact match from ebay and a couple of electrolytic caps (at Carl’s suggestion).

The display is still dim.  Oh well.

 

---> Paul

 

 

From: TriEmbed <triembed-bounces at triembed.org <mailto:triembed-bounces at triembed.org> > On Behalf Of The MacDougals via TriEmbed
Sent: Friday, November 26, 2021 9:11 PM
To: triembed at triembed.org <mailto:triembed at triembed.org> 
Subject: [TriEmbed] Substitute transistor

 

My microwave display suddenly went very dim.  I opened it up and found a discolored

spot on a circuit board feeding the display (see attached image).  That component is

marked B1238, so I assume it is a 2SB1238, which is obsolete.

 

https://www.digikey.com/en/products/base-product/rohm-semiconductor/846/2SB1238/30307

Medium power transistor( 80V, 0.7A) 2SB1189 / 2SB1238 Features 1) High breakdown voltage, BVCEO= 80V, and high current, IC= 0.7A.

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.

 

Anyone want to help me find a replacement?

I dug through my Dad’s stash of old electronics and found a TIP30B, which looks like it might work.

 

 

---> Paul

 

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